Re: [EXTERNAL] Re: Misconduct/terminology

[Alan W Hewat]

OK, thanks Cora. Yes, an internal standard using a simple well
characterised material is a good idea. I perhaps over reacted when you
listed all the parameters you refined for a multi-phase sample, including
ADPs.

Dr Alan Hewat, NeutronOptics
Grenoble, FRANCE (from phone)
alan.he...@neutronoptics.com
+33.476984168 VAT:FR79499450856
http://NeutronOptics.com/hewat
___


On Tue, 16 Jan 2024, 18:05 Lind-Kovacs, Cora,  wrote:

> I should have been more specific – this was not with respect to QPA
> specifically – it was a more general statement about the terminology of
> when we should or shouldn’t use the expression “Rietveld refinement”.
> Although we actually often do Rietveld refinements on 2 phase mixtures,
> where one phase is an internal standard, which we use to determine sample
> height offset changes with temperature.
>
> And no, we don’t just try to get lower R-values by randomly adding
> parameters! 
>
> Cora
>
>
>
> *From:* Alan W Hewat 
> *Sent:* Tuesday, January 16, 2024 11:54 AM
> *To:* Lind-Kovacs, Cora 
> *Cc:* rietveld_l@ill.fr
> *Subject:* Re: [EXTERNAL] Re: Misconduct
>
>
>
>
>
> "In many cases, we will indeed refine those structural parameters to get
> the best possible match".
>
>
>
> The best possible match is not the objective of QPA, but rather the best
> possible estimation of the phase fractions. You can refine parameters
> describing particle size, strain, lattice constants, etc for each phase,
> but please believe the structural coordinates obtained from well
> characterised (usually mono-phase) samples.
>
>
>
> Whether it is structure refinement or phase refinement, please resist the
> temptation to add parameters simply to obtain a lower R-factor.
>
>
>
> 
> Dr Alan Hewat, NeutronOptics
> Grenoble, FRANCE (from phone)
> alan.he...@neutronoptics.com
> +33.476984168 VAT:FR79499450856
> http://NeutronOptics.com/hewat 
> ___
>
>
>
>
> On Tue, 16 Jan 2024, 17:34 Lind-Kovacs, Cora, 
> wrote:
>
> I like Stefan’s view outlined below. In many cases, we will indeed refine
> those structural parameters to get the best possible match. But when I use
> a structural model so that I calculate F(hkl) values, and combine that with
> the ability to vary all kinds of parameters - some structure-related, some
> instrument/setup related, some microstructure related – I would (and have!)
> call that a Rietveld refinement.
>
> Because if I did not, there would be a lot of fun questions to
> contemplate: What if I start doing a Rietveld refinement according to the
> more restrictive definition that has been used in this discussion - and
> then turn off those structural parameters for one reason or another, maybe
> to look into hkl-dependent broadening or such (still constrained by the
> structure in contrast to simple “profile fitting” where any peak can have
> its completely independent parameters!)? Did I just quit doing a Rietveld
> refinement? What if I have a problematic atom, maybe on a split site close
> to an inversion center, and I turn that one off? Do I stop doing a Rietveld
> refinement when I change that variable to “no”? Does any Rietveld
> refinement start out as a “non-Rietveld refinement” when we adjust
> background, lattice parameters, approximate peak shapes and phase
> fractions, to get to a point where we can actually vary the structural
> variables without disastrous consequences? And the moment we touch the
> structural variables, in the same software, suddenly it becomes a Rietveld
> refinement? Do I need to only turn on ADPs, or is the “threshold” that I
> must allow atom positions to refine before I can call it Rietveld? If so,
> do I need to turn on all atom positions or only some of them? What if I
> define rigid bodies, do I still qualify for a Rietveld refinement?
>
> Just some fun thoughts here! 
>
>
>
> Cora
>
>
>
> *From:* rietveld_l-requ...@ill.fr  *On Behalf
> Of *Stefan Seidlmayer
> *Sent:* Tuesday, January 16, 2024 9:51 AM
> *To:* rietveld_l@ill.fr
> *Subject:* [EXTERNAL] Re: Misconduct
>
>
>
> Dear all,
>
>
>
> I was following the discussion also with great interest, as terminology is
> important to distinguish properly between different items.
>
>
>
> To my understanding the Rietveld approach was new because it constrained
> the fitting of a peak list generated "from a structure" with the refinement
> of the profile of the peaks themselves.
>
>
>
> Thus I would have the impression that everytime when we use a
> constrainement of peak list which is generated from a structure and do not
> refine a list of "individual peaks" it is a Rietveld-type refinement.
>
>
>
> A Profile Refinement is/was in my current understanding, when the
> peak/reflection position is not constrained by the structure parameters,
> but can be refined in an arbitrary way, individual for each peak/reflection.
>
> From the positions refined in 

RE: [EXTERNAL] Re: Misconduct/terminology

[Lind-Kovacs, Cora]

I should have been more specific – this was not with respect to QPA 
specifically – it was a more general statement about the terminology of when we 
should or shouldn’t use the expression “Rietveld refinement”.
Although we actually often do Rietveld refinements on 2 phase mixtures, where 
one phase is an internal standard, which we use to determine sample height 
offset changes with temperature.
And no, we don’t just try to get lower R-values by randomly adding parameters! 
Cora

From: Alan W Hewat 
Sent: Tuesday, January 16, 2024 11:54 AM
To: Lind-Kovacs, Cora 
Cc: rietveld_l@ill.fr
Subject: Re: [EXTERNAL] Re: Misconduct


"In many cases, we will indeed refine those structural parameters to get the 
best possible match".

The best possible match is not the objective of QPA, but rather the best 
possible estimation of the phase fractions. You can refine parameters 
describing particle size, strain, lattice constants, etc for each phase, but 
please believe the structural coordinates obtained from well characterised 
(usually mono-phase) samples.

Whether it is structure refinement or phase refinement, please resist the 
temptation to add parameters simply to obtain a lower R-factor.


Dr Alan Hewat, NeutronOptics
Grenoble, FRANCE (from phone)
alan.he...@neutronoptics.com
+33.476984168 VAT:FR79499450856
http://NeutronOptics.com/hewat
___


On Tue, 16 Jan 2024, 17:34 Lind-Kovacs, Cora, 
mailto:cora.l...@utoledo.edu>> wrote:
I like Stefan’s view outlined below. In many cases, we will indeed refine those 
structural parameters to get the best possible match. But when I use a 
structural model so that I calculate F(hkl) values, and combine that with the 
ability to vary all kinds of parameters - some structure-related, some 
instrument/setup related, some microstructure related – I would (and have!) 
call that a Rietveld refinement.
Because if I did not, there would be a lot of fun questions to contemplate: 
What if I start doing a Rietveld refinement according to the more restrictive 
definition that has been used in this discussion - and then turn off those 
structural parameters for one reason or another, maybe to look into 
hkl-dependent broadening or such (still constrained by the structure in 
contrast to simple “profile fitting” where any peak can have its completely 
independent parameters!)? Did I just quit doing a Rietveld refinement? What if 
I have a problematic atom, maybe on a split site close to an inversion center, 
and I turn that one off? Do I stop doing a Rietveld refinement when I change 
that variable to “no”? Does any Rietveld refinement start out as a 
“non-Rietveld refinement” when we adjust background, lattice parameters, 
approximate peak shapes and phase fractions, to get to a point where we can 
actually vary the structural variables without disastrous consequences? And the 
moment we touch the structural variables, in the same software, suddenly it 
becomes a Rietveld refinement? Do I need to only turn on ADPs, or is the 
“threshold” that I must allow atom positions to refine before I can call it 
Rietveld? If so, do I need to turn on all atom positions or only some of them? 
What if I define rigid bodies, do I still qualify for a Rietveld refinement?
Just some fun thoughts here! 

Cora

From: rietveld_l-requ...@ill.fr 
mailto:rietveld_l-requ...@ill.fr>> On Behalf Of 
Stefan Seidlmayer
Sent: Tuesday, January 16, 2024 9:51 AM
To: rietveld_l@ill.fr
Subject: [EXTERNAL] Re: Misconduct

Dear all,

I was following the discussion also with great interest, as terminology is 
important to distinguish properly between different items.

To my understanding the Rietveld approach was new because it constrained the 
fitting of a peak list generated "from a structure" with the refinement of the 
profile of the peaks themselves.

Thus I would have the impression that everytime when we use a constrainement of 
peak list which is generated from a structure and do not refine a list of 
"individual peaks" it is a Rietveld-type refinement.

A Profile Refinement is/was in my current understanding, when the 
peak/reflection position is not constrained by the structure parameters, but 
can be refined in an arbitrary way, individual for each peak/reflection.
From the positions refined in this way, one could then determine cell parameter 
etc. But this would require a secondary step. First refine all found 
peaks/reflection with a common profile. Then determine the lattice parameters 
from the refined peak positions etc.
This is also troublesome as without prior structure "knowledge" it may and 
surely is that certain reflection which in fact are overlapping multiple 
reflections are improperly identified as "one" reflection.
This is very the neatness of the Rietveld approach comes into play, as it 
generates even 

Re: [EXTERNAL] Re: Misconduct

[Alan W Hewat]

"In many cases, we will indeed refine those structural parameters to get
the best possible match".

The best possible match is not the objective of QPA, but rather the best
possible estimation of the phase fractions. You can refine parameters
describing particle size, strain, lattice constants, etc for each phase,
but please believe the structural coordinates obtained from well
characterised (usually mono-phase) samples.

Whether it is structure refinement or phase refinement, please resist the
temptation to add parameters simply to obtain a lower R-factor.


Dr Alan Hewat, NeutronOptics
Grenoble, FRANCE (from phone)
alan.he...@neutronoptics.com
+33.476984168 VAT:FR79499450856
http://NeutronOptics.com/hewat
___


On Tue, 16 Jan 2024, 17:34 Lind-Kovacs, Cora,  wrote:

> I like Stefan’s view outlined below. In many cases, we will indeed refine
> those structural parameters to get the best possible match. But when I use
> a structural model so that I calculate F(hkl) values, and combine that with
> the ability to vary all kinds of parameters - some structure-related, some
> instrument/setup related, some microstructure related – I would (and have!)
> call that a Rietveld refinement.
>
> Because if I did not, there would be a lot of fun questions to
> contemplate: What if I start doing a Rietveld refinement according to the
> more restrictive definition that has been used in this discussion - and
> then turn off those structural parameters for one reason or another, maybe
> to look into hkl-dependent broadening or such (still constrained by the
> structure in contrast to simple “profile fitting” where any peak can have
> its completely independent parameters!)? Did I just quit doing a Rietveld
> refinement? What if I have a problematic atom, maybe on a split site close
> to an inversion center, and I turn that one off? Do I stop doing a Rietveld
> refinement when I change that variable to “no”? Does any Rietveld
> refinement start out as a “non-Rietveld refinement” when we adjust
> background, lattice parameters, approximate peak shapes and phase
> fractions, to get to a point where we can actually vary the structural
> variables without disastrous consequences? And the moment we touch the
> structural variables, in the same software, suddenly it becomes a Rietveld
> refinement? Do I need to only turn on ADPs, or is the “threshold” that I
> must allow atom positions to refine before I can call it Rietveld? If so,
> do I need to turn on all atom positions or only some of them? What if I
> define rigid bodies, do I still qualify for a Rietveld refinement?
>
> Just some fun thoughts here! 
>
>
>
> Cora
>
>
>
> *From:* rietveld_l-requ...@ill.fr  *On Behalf
> Of *Stefan Seidlmayer
> *Sent:* Tuesday, January 16, 2024 9:51 AM
> *To:* rietveld_l@ill.fr
> *Subject:* [EXTERNAL] Re: Misconduct
>
>
>
> Dear all,
>
>
>
> I was following the discussion also with great interest, as terminology is
> important to distinguish properly between different items.
>
>
>
> To my understanding the Rietveld approach was new because it constrained
> the fitting of a peak list generated "from a structure" with the refinement
> of the profile of the peaks themselves.
>
>
>
> Thus I would have the impression that everytime when we use a
> constrainement of peak list which is generated from a structure and do not
> refine a list of "individual peaks" it is a Rietveld-type refinement.
>
>
>
> A Profile Refinement is/was in my current understanding, when the
> peak/reflection position is not constrained by the structure parameters,
> but can be refined in an arbitrary way, individual for each peak/reflection.
>
> From the positions refined in this way, one could then determine cell
> parameter etc. But this would require a secondary step. First refine all
> found peaks/reflection with a common profile. Then determine the lattice
> parameters from the refined peak positions etc.
>
> This is also troublesome as without prior structure "knowledge" it may and
> surely is that certain reflection which in fact are overlapping multiple
> reflections are improperly identified as "one" reflection.
>
> This is very the neatness of the Rietveld approach comes into play, as it
> generates even overlapping reflections which then generate the total
> profile by constraining them with the profile parameters.
>
>
>
> So the main point in differentiation is then in my eyes:
>
> Rietveld-Refinement: The use of a structure generated peak list which is
> constrained with profile parameters.
>
>
>
> Profile-Refinement: Profile refinement can work on individual peaks with
> NO structure information at all.
>
>
>
> Pawley-Refinement then is logically a little bit of a Hybrid, as the
> reflection list is pre-generated from the structure. But the intensities
> are just matched to best fit the profile. While in a true Rietveld even the
> reflection intensities is always generated from the underlying 

Re: Misconduct/terminology

[EVANS, IVANA R.]

Dear Alan,

No problems with “Rietveld refinement” at all, despite the fact that I met Hugo 
Rietveld when I was a young postdoc at 1999 IUCr and he seemed rather refined 
to me, too. And it’s not my students I’m concerned about - they take me 
surprisingly seriously, on issues of refinement and (classical and modern) 
languages alike. 

Ivana


On 16 Jan 2024, at 16:23, Alan W Hewat  wrote:


[EXTERNAL EMAIL]
Dear Smudut.
Potatoes in gives Potatoes out from black box software with buttons.

Dear Ivana.
Do you also have a problem with the shorthand expression "Rietveld Refinement"? 
If so, you might try my joke that Rietveld is already refined :-) I think you 
can use such apparent mis-statements to teach your students what is really 
refined - neither data nor datum.

Alan


Dr Alan Hewat, NeutronOptics
Grenoble, FRANCE (from phone)
alan.he...@neutronoptics.com
+33.476984168 VAT:FR79499450856
http://NeutronOptics.com/hewat
___


On Tue, 16 Jan 2024, 17:17 Norberto Masciocchi, 
mailto:norberto.mascioc...@uninsubria.it>> 
wrote:
Il 16/01/2024 17:06, EVANS, IVANA R. ha scritto:

Dear All,
Data shold be NEVER refined, no matter whether "data£ is considered singular or 
plural. It's the model which is refined.
Beyound this, "data" is plural, as it is the plural of "datum".
https://dictionary.cambridge.org/dictionary/english/datum

Norberto
Dear Alan/All,

I have a problem with that shorthand expression, particularly in teaching and 
training contexts, because students quickly equate this to “refining the data”. 
Countless research papers, even coming from reputable groups and published in 
reputable journals, contain statements that “X-ray data were/was refined…”.

Being old-fashioned, I can just about take “data” in singular. However, 
“refining one’s experimental data points” is a different matter.

Best,
Ivana

**
Ivana Radosavljevic Evans
Professor in Structural/Materials Chemistry
Department of Chemistry
Durham University
Durham DH1 3LE, U.K.
Office: CG 244
Phone: (0191) 334-2594
**

On 16 Jan 2024, at 15:47, Alan W Hewat 
 wrote:


[EXTERNAL EMAIL]
"QPA Profile Refinement" is shorthand for "QPA (using the) Profile (method of) 
Refinement :-)

Yes, it is the phase composition that is refined, by fitting the profile, but I 
see no problem with the shorthand expression.


Dr Alan Hewat, NeutronOptics
Grenoble, FRANCE (from phone)
alan.he...@neutronoptics.com
+33.476984168 VAT:FR79499450856
http://NeutronOptics.com/hewat
___


On Tue, 16 Jan 2024, 16:38 , 
mailto:alberto.martine...@spin.cnr.it>> wrote:
Il 2024-01-16 16:21 Alan W Hewat ha scritto:
>
> And for those who worry about pedantry, "Rietveld Refinement" is just
> shorthand for the "Rietveld (method of) Refinement. It involves the
> refinement of the crystal structure, not Rietveld :-)

Indeed! :-) Nonetheless, whatever the analysis, the profile is never
refined, it is fitted. So I would avoid the misleading use of “profile
refinement”.

not a big deal, just terminology. Having said my opinion, I return to
silently follow this interesting discussion.
Alberto
++
Please do NOT attach files to the whole list 

Send commands to  eg: HELP as the 
subject with no body text
The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/
++




++
Please do NOT attach files to the whole list 

Send commands to  eg: HELP as the 
subject with no body text
The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/
++




--
Norberto Masciocchi
Professor of Chemistry
Department of Science and High Technology & To.Sca.Lab.
University of Insubria
Via Valleggio, 11
22100 Como - Italy
E-mail: 
norberto.mascioc...@uninsubria.it
Tel: +39-031-2386613
Skype: norberto.masciocchi
Website: toscalab.uninsubria.it
**
Hago cosas que me quitan un poco el mal gusto del vacío.
Y ésa es en el fondo la mejor definición del homo sapiens (J. Cortàzar)
**
Justice is nothing more than the advantage of the stronger (Thrasymachus)
**
Freedom is just another word for nothing is left to lose (K. Kristofferson)

Re: Misconduct

[Luca Lutterotti]



That’s the best message of the year!

I should remember it.

Luca


> On 16 Jan 2024, at 15:22, Alan W Hewat  wrote:
> 
> Ha ! When Terry Sabine proposed to call it Rietveld Refinement, I told him 
> that Rietveld was already "refined". 
> 
> 
> Dr Alan Hewat, NeutronOptics
> Grenoble, FRANCE (from phone)
> alan.he...@neutronoptics.com
> +33.476984168 VAT:FR79499450856
> http://NeutronOptics.com/hewat 
> ___
>
> 
> On Tue, 16 Jan 2024, 15:11 ,  > wrote:
>> Dear all,
>> 
>> I'm following this interesting discussion. It seems to me that sometimes 
>> there is an improper use of terminology, in particular when we talk 
>> about "profile refinement"; in reality, we all know that it is about 
>> "profile fitting". Or did I miss something?
>> 
>> sorry for the pedantry.
>> Alberto
>> ++
>> Please do NOT attach files to the whole list 
>> Send commands to mailto:lists...@ill.fr>> eg: HELP as the 
>> subject with no body text
>> The Rietveld_L list archive is on 
>> http://www.mail-archive.com/rietveld_l@ill.fr/
>> ++
>> 
> ++
> Please do NOT attach files to the whole list 
> Send commands to  eg: HELP as the subject with no body text
> The Rietveld_L list archive is on 
> http://www.mail-archive.com/rietveld_l@ill.fr/
> ++
> 

++
Please do NOT attach files to the whole list 
Send commands to  eg: HELP as the subject with no body text
The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/
++

RE: [EXTERNAL] Re: Misconduct

[Lind-Kovacs, Cora]

I like Stefan’s view outlined below. In many cases, we will indeed refine those 
structural parameters to get the best possible match. But when I use a 
structural model so that I calculate F(hkl) values, and combine that with the 
ability to vary all kinds of parameters - some structure-related, some 
instrument/setup related, some microstructure related – I would (and have!) 
call that a Rietveld refinement.
Because if I did not, there would be a lot of fun questions to contemplate: 
What if I start doing a Rietveld refinement according to the more restrictive 
definition that has been used in this discussion - and then turn off those 
structural parameters for one reason or another, maybe to look into 
hkl-dependent broadening or such (still constrained by the structure in 
contrast to simple “profile fitting” where any peak can have its completely 
independent parameters!)? Did I just quit doing a Rietveld refinement? What if 
I have a problematic atom, maybe on a split site close to an inversion center, 
and I turn that one off? Do I stop doing a Rietveld refinement when I change 
that variable to “no”? Does any Rietveld refinement start out as a 
“non-Rietveld refinement” when we adjust background, lattice parameters, 
approximate peak shapes and phase fractions, to get to a point where we can 
actually vary the structural variables without disastrous consequences? And the 
moment we touch the structural variables, in the same software, suddenly it 
becomes a Rietveld refinement? Do I need to only turn on ADPs, or is the 
“threshold” that I must allow atom positions to refine before I can call it 
Rietveld? If so, do I need to turn on all atom positions or only some of them? 
What if I define rigid bodies, do I still qualify for a Rietveld refinement?
Just some fun thoughts here! 

Cora

From: rietveld_l-requ...@ill.fr  On Behalf Of Stefan 
Seidlmayer
Sent: Tuesday, January 16, 2024 9:51 AM
To: rietveld_l@ill.fr
Subject: [EXTERNAL] Re: Misconduct

Dear all,

I was following the discussion also with great interest, as terminology is 
important to distinguish properly between different items.

To my understanding the Rietveld approach was new because it constrained the 
fitting of a peak list generated "from a structure" with the refinement of the 
profile of the peaks themselves.

Thus I would have the impression that everytime when we use a constrainement of 
peak list which is generated from a structure and do not refine a list of 
"individual peaks" it is a Rietveld-type refinement.

A Profile Refinement is/was in my current understanding, when the 
peak/reflection position is not constrained by the structure parameters, but 
can be refined in an arbitrary way, individual for each peak/reflection.
From the positions refined in this way, one could then determine cell parameter 
etc. But this would require a secondary step. First refine all found 
peaks/reflection with a common profile. Then determine the lattice parameters 
from the refined peak positions etc.
This is also troublesome as without prior structure "knowledge" it may and 
surely is that certain reflection which in fact are overlapping multiple 
reflections are improperly identified as "one" reflection.
This is very the neatness of the Rietveld approach comes into play, as it 
generates even overlapping reflections which then generate the total profile by 
constraining them with the profile parameters.

So the main point in differentiation is then in my eyes:
Rietveld-Refinement: The use of a structure generated peak list which is 
constrained with profile parameters.

Profile-Refinement: Profile refinement can work on individual peaks with NO 
structure information at all.

Pawley-Refinement then is logically a little bit of a Hybrid, as the reflection 
list is pre-generated from the structure. But the intensities are just matched 
to best fit the profile. While in a true Rietveld even the reflection 
intensities is always generated from the underlying structure model applied in 
the Rietveld refinement.

What do you think of this point of view? Am I overlooking something?

Best regards

Stefan Seidlmayer



Am Di., 16. Jan. 2024 um 15:23 Uhr schrieb Alan W Hewat 
mailto:alan.he...@neutronoptics.com>>:
Ha ! When Terry Sabine proposed to call it Rietveld Refinement, I told him that 
Rietveld was already "refined".


Dr Alan Hewat, NeutronOptics
Grenoble, FRANCE (from phone)
alan.he...@neutronoptics.com
+33.476984168 VAT:FR79499450856
http://NeutronOptics.com/hewat
___


On Tue, 16 Jan 2024, 15:11 , 
mailto:alberto.martine...@spin.cnr.it>> wrote:
Dear all,

I'm following this interesting discussion. It seems to me that sometimes
there is an improper use of terminology, in particular when we talk
about "profile refinement"; in reality, we all know that it is about
"profile fitting". Or did I miss something?

Re: Misconduct/terminology

[Alan W Hewat]

Dear Smudut.
Potatoes in gives Potatoes out from black box software with buttons.

Dear Ivana.
Do you also have a problem with the shorthand expression "Rietveld
Refinement"? If so, you might try my joke that Rietveld is already refined
:-) I think you can use such apparent mis-statements to teach your students
what is really refined - neither data nor datum.

Alan


Dr Alan Hewat, NeutronOptics
Grenoble, FRANCE (from phone)
alan.he...@neutronoptics.com
+33.476984168 VAT:FR79499450856
http://NeutronOptics.com/hewat
___


On Tue, 16 Jan 2024, 17:17 Norberto Masciocchi, <
norberto.mascioc...@uninsubria.it> wrote:

> Il 16/01/2024 17:06, EVANS, IVANA R. ha scritto:
>
> Dear All,
> Data shold be NEVER refined, no matter whether "data£ is considered
> singular or plural. It's the model which is refined.
> Beyound this, "data" is plural, as it is the plural of "datum".
> https://dictionary.cambridge.org/dictionary/english/datum
>
> Norberto
>
> Dear Alan/All,
>
> I have a problem with that shorthand expression, particularly in teaching
> and training contexts, because students quickly equate this to “refining
> the data”. Countless research papers, even coming from reputable groups and
> published in reputable journals, contain statements that “X-ray data
> were/was refined…”.
>
> Being old-fashioned, I can just about take “data” in singular. However,
> “refining one’s experimental data points” is a different matter.
>
> Best,
> Ivana
>
>
> **
>
> Ivana Radosavljevic Evans
>
> Professor in Structural/Materials Chemistry
>
> Department of Chemistry
>
> Durham University
>
> Durham DH1 3LE, U.K.
>
> Office: CG 244
>
> Phone: (0191) 334-2594
>
> **
>
> On 16 Jan 2024, at 15:47, Alan W Hewat 
>  wrote:
>
> 
> *[EXTERNAL EMAIL]*
> "QPA Profile Refinement" is shorthand for "QPA (using the) Profile (method
> of) Refinement :-)
>
> Yes, it is the phase composition that is refined, by fitting the profile,
> but I see no problem with the shorthand expression.
>
> 
> Dr Alan Hewat, NeutronOptics
> Grenoble, FRANCE (from phone)
> alan.he...@neutronoptics.com
> +33.476984168 VAT:FR79499450856
> http://NeutronOptics.com/hewat 
> ___
>
>
> On Tue, 16 Jan 2024, 16:38 ,  wrote:
>
>> Il 2024-01-16 16:21 Alan W Hewat ha scritto:
>> >
>> > And for those who worry about pedantry, "Rietveld Refinement" is just
>> > shorthand for the "Rietveld (method of) Refinement. It involves the
>> > refinement of the crystal structure, not Rietveld :-)
>>
>> Indeed! :-) Nonetheless, whatever the analysis, the profile is never
>> refined, it is fitted. So I would avoid the misleading use of “profile
>> refinement”.
>>
>> not a big deal, just terminology. Having said my opinion, I return to
>> silently follow this interesting discussion.
>> Alberto
>>
> ++
> Please do NOT attach files to the whole list
>  
> Send commands to   eg: HELP as the
> subject with no body text
> The Rietveld_L list archive is on
> http://www.mail-archive.com/rietveld_l@ill.fr/
> ++
>
>
> ++
> Please do NOT attach files to the whole list  
> 
> Send commands to   eg: HELP as the subject 
> with no body text
> The Rietveld_L list archive is on 
> http://www.mail-archive.com/rietveld_l@ill.fr/
> ++
>
>
>
> --
> Norberto Masciocchi
> Professor of Chemistry
> Department of Science and High Technology & To.Sca.Lab.
> University of Insubria
> Via Valleggio, 11
> 22100 Como - Italy
> E-mail: norberto.mascioc...@uninsubria.it
> Tel: +39-031-2386613
> Skype: norberto.masciocchi
> Website: toscalab.uninsubria.it
> **
> Hago cosas que me quitan un poco el mal gusto del vacío.
> Y ésa es en el fondo la mejor definición del homo sapiens (J. Cortàzar)
> **
> Justice is nothing more than the advantage of the stronger (Thrasymachus)
> **
> Freedom is just another word for nothing is left to lose (K. Kristofferson)
>
> ++
> Please do NOT attach files to the whole list  >
> Send commands to  eg: HELP as the subject with no body
> text
> The Rietveld_L list archive is on
> http://www.mail-archive.com/rietveld_l@ill.fr/
> ++
>
>
++
Please do NOT attach files to the whole list 
Send commands to  eg: HELP as the subject with no body text
The Rietveld_L list archive is on 

RE: Misconduct/terminology

[Cline, James P. Dr. (Fed)]

Bravo!!!


James P. Cline
Materials Measurement Science Division
National Institute of Standards and Technology
100 Bureau Dr. stop 8370 [ B113 / Bldg 217 ]
Gaithersburg, MD 20899-8523USA
james.cl...@nist.gov
https://www.nist.gov/people/james-p-cline
(301) 975 5793

From: rietveld_l-requ...@ill.fr  On Behalf Of 
Norberto Masciocchi
Sent: Tuesday, January 16, 2024 11:15 AM
To: rietveld_l@ill.fr
Subject: Re: Misconduct/terminology

Il 16/01/2024 17:06, EVANS, IVANA R. ha scritto:

Dear All,
Data shold be NEVER refined, no matter whether "data£ is considered singular or 
plural. It's the model which is refined.
Beyound this, "data" is plural, as it is the plural of "datum".
https://dictionary.cambridge.org/dictionary/english/datum

Norberto
Dear Alan/All,

I have a problem with that shorthand expression, particularly in teaching and 
training contexts, because students quickly equate this to “refining the data”. 
Countless research papers, even coming from reputable groups and published in 
reputable journals, contain statements that “X-ray data were/was refined…”.

Being old-fashioned, I can just about take “data” in singular. However, 
“refining one’s experimental data points” is a different matter.

Best,
Ivana

**
Ivana Radosavljevic Evans
Professor in Structural/Materials Chemistry
Department of Chemistry
Durham University
Durham DH1 3LE, U.K.
Office: CG 244
Phone: (0191) 334-2594
**


On 16 Jan 2024, at 15:47, Alan W Hewat 
 wrote:

[EXTERNAL EMAIL]
"QPA Profile Refinement" is shorthand for "QPA (using the) Profile (method of) 
Refinement :-)

Yes, it is the phase composition that is refined, by fitting the profile, but I 
see no problem with the shorthand expression.


Dr Alan Hewat, NeutronOptics
Grenoble, FRANCE (from phone)
alan.he...@neutronoptics.com
+33.476984168 VAT:FR79499450856
http://NeutronOptics.com/hewat
___


On Tue, 16 Jan 2024, 16:38 , 
mailto:alberto.martine...@spin.cnr.it>> wrote:
Il 2024-01-16 16:21 Alan W Hewat ha scritto:
>
> And for those who worry about pedantry, "Rietveld Refinement" is just
> shorthand for the "Rietveld (method of) Refinement. It involves the
> refinement of the crystal structure, not Rietveld :-)

Indeed! :-) Nonetheless, whatever the analysis, the profile is never
refined, it is fitted. So I would avoid the misleading use of “profile
refinement”.

not a big deal, just terminology. Having said my opinion, I return to
silently follow this interesting discussion.
Alberto
++
Please do NOT attach files to the whole list 

Send commands to  eg: HELP as the 
subject with no body text
The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/
++



++

Please do NOT attach files to the whole list 


Send commands to  eg: HELP as the 
subject with no body text

The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/

++





--

Norberto Masciocchi

Professor of Chemistry

Department of Science and High Technology & To.Sca.Lab.

University of Insubria

Via Valleggio, 11

22100 Como - Italy

E-mail: 
norberto.mascioc...@uninsubria.it

Tel: +39-031-2386613

Skype: norberto.masciocchi

Website: toscalab.uninsubria.it

**

Hago cosas que me quitan un poco el mal gusto del vacío.

Y ésa es en el fondo la mejor definición del homo sapiens (J. Cortàzar)

**

Justice is nothing more than the advantage of the stronger (Thrasymachus)

**

Freedom is just another word for nothing is left to lose (K. Kristofferson)
++
Please do NOT attach files to the whole list 
Send commands to  eg: HELP as the subject with no body text
The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/
++

Re: Misconduct/terminology

[Norberto Masciocchi]

Il 16/01/2024 17:06, EVANS, IVANA R. ha scritto:

Dear All,
Data shold be NEVER refined, no matter whether "data£ is considered 
singular or plural. It's the model which is refined.

Beyound this, "data" is plural, as it is the plural of "datum".
https://dictionary.cambridge.org/dictionary/english/datum

Norberto

Dear Alan/All,

I have a problem with that shorthand expression, particularly in 
teaching and training contexts, because students quickly equate this 
to “refining the data”. Countless research papers, even coming from 
reputable groups and published in reputable journals, contain 
statements that “X-ray data were/was refined…”.


Being old-fashioned, I can just about take “data” in singular. 
However, “refining one’s experimental data points” is a different matter.


Best,
Ivana


**

Ivana Radosavljevic Evans

Professor in Structural/Materials Chemistry

Department of Chemistry

Durham University

Durham DH1 3LE, U.K.

Office: CG 244

Phone: (0191) 334-2594

**


On 16 Jan 2024, at 15:47, Alan W Hewat  
wrote:



*[EXTERNAL EMAIL]*
"QPA Profile Refinement" is shorthand for "QPA (using the) Profile 
(method of) Refinement :-)


Yes, it is the phase composition that is refined, by fitting the 
profile, but I see no problem with the shorthand expression.



Dr Alan Hewat, NeutronOptics
Grenoble, FRANCE (from phone)
alan.he...@neutronoptics.com
+33.476984168 VAT:FR79499450856
http://NeutronOptics.com/hewat 
___

On Tue, 16 Jan 2024, 16:38 ,  wrote:

Il 2024-01-16 16:21 Alan W Hewat ha scritto:
>
> And for those who worry about pedantry, "Rietveld Refinement"
is just
> shorthand for the "Rietveld (method of) Refinement. It involves the
> refinement of the crystal structure, not Rietveld :-)

Indeed! :-) Nonetheless, whatever the analysis, the profile is never
refined, it is fitted. So I would avoid the misleading use of
“profile
refinement”.

not a big deal, just terminology. Having said my opinion, I
return to
silently follow this interesting discussion.
Alberto

++
Please do NOT attach files to the whole list 

Send commands to  eg: HELP as the subject with no 
body text
The Rietveld_L list archive is on 
http://www.mail-archive.com/rietveld_l@ill.fr/

++



++
Please do NOT attach files to the whole list
Send commands to  eg: HELP as the subject with no body text
The Rietveld_L list archive is onhttp://www.mail-archive.com/rietveld_l@ill.fr/
++



--
Norberto Masciocchi
Professor of Chemistry
Department of Science and High Technology & To.Sca.Lab.
University of Insubria
Via Valleggio, 11
22100 Como - Italy
E-mail:norberto.mascioc...@uninsubria.it   
Tel: +39-031-2386613

Skype: norberto.masciocchi
Website: toscalab.uninsubria.it
**
Hago cosas que me quitan un poco el mal gusto del vacío.
Y ésa es en el fondo la mejor definición del homo sapiens (J. Cortàzar)
**
Justice is nothing more than the advantage of the stronger (Thrasymachus)
**
Freedom is just another word for nothing is left to lose (K. Kristofferson)
++
Please do NOT attach files to the whole list 
Send commands to  eg: HELP as the subject with no body text
The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/
++

Re: Misconduct/terminology

[Smudut]

Potato-potato...Software that I am using for QPA has one button named "Rietveld refinemet" so for me it is Rietveld refinement Poslano iz Outlook za Android
++
Please do NOT attach files to the whole list 
Send commands to  eg: HELP as the subject with no body text
The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/
++

Re: Misconduct/terminology

[EVANS, IVANA R.]

Dear Alan/All,

I have a problem with that shorthand expression, particularly in teaching and 
training contexts, because students quickly equate this to “refining the data”. 
Countless research papers, even coming from reputable groups and published in 
reputable journals, contain statements that “X-ray data were/was refined…”.

Being old-fashioned, I can just about take “data” in singular. However, 
“refining one’s experimental data points” is a different matter.

Best,
Ivana

**
Ivana Radosavljevic Evans
Professor in Structural/Materials Chemistry
Department of Chemistry
Durham University
Durham DH1 3LE, U.K.
Office: CG 244
Phone: (0191) 334-2594
**

On 16 Jan 2024, at 15:47, Alan W Hewat  wrote:


[EXTERNAL EMAIL]
"QPA Profile Refinement" is shorthand for "QPA (using the) Profile (method of) 
Refinement :-)

Yes, it is the phase composition that is refined, by fitting the profile, but I 
see no problem with the shorthand expression.


Dr Alan Hewat, NeutronOptics
Grenoble, FRANCE (from phone)
alan.he...@neutronoptics.com
+33.476984168 VAT:FR79499450856
http://NeutronOptics.com/hewat
___


On Tue, 16 Jan 2024, 16:38 , 
mailto:alberto.martine...@spin.cnr.it>> wrote:
Il 2024-01-16 16:21 Alan W Hewat ha scritto:
>
> And for those who worry about pedantry, "Rietveld Refinement" is just
> shorthand for the "Rietveld (method of) Refinement. It involves the
> refinement of the crystal structure, not Rietveld :-)

Indeed! :-) Nonetheless, whatever the analysis, the profile is never
refined, it is fitted. So I would avoid the misleading use of “profile
refinement”.

not a big deal, just terminology. Having said my opinion, I return to
silently follow this interesting discussion.
Alberto
++
Please do NOT attach files to the whole list 
Send commands to  eg: HELP as the subject with no body text
The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/
++

++
Please do NOT attach files to the whole list 
Send commands to  eg: HELP as the subject with no body text
The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/
++

Re: Misconduct

[Alan W Hewat]

"QPA Profile Refinement" is shorthand for "QPA (using the) Profile (method
of) Refinement :-)

Yes, it is the phase composition that is refined, by fitting the profile,
but I see no problem with the shorthand expression.


Dr Alan Hewat, NeutronOptics
Grenoble, FRANCE (from phone)
alan.he...@neutronoptics.com
+33.476984168 VAT:FR79499450856
http://NeutronOptics.com/hewat
___


On Tue, 16 Jan 2024, 16:38 ,  wrote:

> Il 2024-01-16 16:21 Alan W Hewat ha scritto:
> >
> > And for those who worry about pedantry, "Rietveld Refinement" is just
> > shorthand for the "Rietveld (method of) Refinement. It involves the
> > refinement of the crystal structure, not Rietveld :-)
>
> Indeed! :-) Nonetheless, whatever the analysis, the profile is never
> refined, it is fitted. So I would avoid the misleading use of “profile
> refinement”.
>
> not a big deal, just terminology. Having said my opinion, I return to
> silently follow this interesting discussion.
> Alberto
>
++
Please do NOT attach files to the whole list 
Send commands to  eg: HELP as the subject with no body text
The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/
++

Re: Misconduct

[alberto . martinelli]

Il 2024-01-16 16:21 Alan W Hewat ha scritto:


And for those who worry about pedantry, "Rietveld Refinement" is just
shorthand for the "Rietveld (method of) Refinement. It involves the
refinement of the crystal structure, not Rietveld :-)


Indeed! :-) Nonetheless, whatever the analysis, the profile is never 
refined, it is fitted. So I would avoid the misleading use of “profile 
refinement”.


not a big deal, just terminology. Having said my opinion, I return to 
silently follow this interesting discussion.

Alberto
++
Please do NOT attach files to the whole list 
Send commands to  eg: HELP as the subject with no body text
The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/
++

Re: Misconduct

[Alan W Hewat]

Yes Stefan, it is a question of what you are refining and constraining.
Before Rietveld it was of course known that the positions of the peaks were
determined by the unit cell. There were techniques like Search-Match that
attempted to identify materials by the positions of the peaks. The history
of phase analysis is older than Rietveld. The Petten group were not
interested in QPA, but instead in refining the crystal and magnetic
structures of specific materials.

If Rietveld had never existed, it is reasonable to assume that QPA would
still have evolved much as it has today, refining the phase content from
the whole profile, without trying to refine structures of mixed phases.

And for those who worry about pedantry, "Rietveld Refinement" is just
shorthand for the "Rietveld (method of) Refinement. It involves the
refinement of the crystal structure, not Rietveld :-)

Finally Kurt, perhaps as individuals we can't change the world, but if we
are concerned that people are debasing our scientific techniques, we can
expose them as Armel did. Or at least we can refuse to co-author such
papers, and reject them as journal editors. As authors and referees we can
correct sloppy use of terminology. This paper is wrong on so many levels,
apart from the apparent "misconduct" and the incorrect label of Rietveld
Refinement.

Dr Alan Hewat, NeutronOptics
Grenoble, FRANCE (from phone)
alan.he...@neutronoptics.com
+33.476984168 VAT:FR79499450856
http://NeutronOptics.com/hewat
___


On Tue, 16 Jan 2024, 15:50 Stefan Seidlmayer,  wrote:

> Dear all,
>
> I was following the discussion also with great interest, as terminology is
> important to distinguish properly between different items.
>
> To my understanding the Rietveld approach was new because it constrained
> the fitting of a peak list generated "from a structure" with the refinement
> of the profile of the peaks themselves.
>
> Thus I would have the impression that everytime when we use a
> constrainement of peak list which is generated from a structure and do not
> refine a list of "individual peaks" it is a Rietveld-type refinement.
>
> A Profile Refinement is/was in my current understanding, when the
> peak/reflection position is not constrained by the structure parameters,
> but can be refined in an arbitrary way, individual for each peak/reflection.
> From the positions refined in this way, one could then determine cell
> parameter etc. But this would require a secondary step. First refine all
> found peaks/reflection with a common profile. Then determine the lattice
> parameters from the refined peak positions etc.
> This is also troublesome as without prior structure "knowledge" it may and
> surely is that certain reflection which in fact are overlapping multiple
> reflections are improperly identified as "one" reflection.
> This is very the neatness of the Rietveld approach comes into play, as it
> generates even overlapping reflections which then generate the total
> profile by constraining them with the profile parameters.
>
> So the main point in differentiation is then in my eyes:
> Rietveld-Refinement: The use of a structure generated peak list which is
> constrained with profile parameters.
>
> Profile-Refinement: Profile refinement can work on individual peaks with
> NO structure information at all.
>
> Pawley-Refinement then is logically a little bit of a Hybrid, as the
> reflection list is pre-generated from the structure. But the intensities
> are just matched to best fit the profile. While in a true Rietveld even the
> reflection intensities is always generated from the underlying structure
> model applied in the Rietveld refinement.
>
> What do you think of this point of view? Am I overlooking something?
>
> Best regards
>
> Stefan Seidlmayer
>
>
>
> Am Di., 16. Jan. 2024 um 15:23 Uhr schrieb Alan W Hewat <
> alan.he...@neutronoptics.com>:
>
>> Ha ! When Terry Sabine proposed to call it Rietveld Refinement, I told
>> him that Rietveld was already "refined".
>>
>> 
>> Dr Alan Hewat, NeutronOptics
>> Grenoble, FRANCE (from phone)
>> alan.he...@neutronoptics.com
>> +33.476984168 VAT:FR79499450856
>> http://NeutronOptics.com/hewat
>> ___
>>
>>
>> On Tue, 16 Jan 2024, 15:11 ,  wrote:
>>
>>> Dear all,
>>>
>>> I'm following this interesting discussion. It seems to me that sometimes
>>> there is an improper use of terminology, in particular when we talk
>>> about "profile refinement"; in reality, we all know that it is about
>>> "profile fitting". Or did I miss something?
>>>
>>> sorry for the pedantry.
>>> Alberto
>>> ++
>>> Please do NOT attach files to the whole list
>>> 
>>> Send commands to  eg: HELP as the subject with no body
>>> text
>>> The Rietveld_L list archive is on
>>> http://www.mail-archive.com/rietveld_l@ill.fr/
>>> 

Re: Misconduct

[Stefan Seidlmayer]

Dear all,

I was following the discussion also with great interest, as terminology is
important to distinguish properly between different items.

To my understanding the Rietveld approach was new because it constrained
the fitting of a peak list generated "from a structure" with the refinement
of the profile of the peaks themselves.

Thus I would have the impression that everytime when we use a
constrainement of peak list which is generated from a structure and do not
refine a list of "individual peaks" it is a Rietveld-type refinement.

A Profile Refinement is/was in my current understanding, when the
peak/reflection position is not constrained by the structure parameters,
but can be refined in an arbitrary way, individual for each peak/reflection.
>From the positions refined in this way, one could then determine cell
parameter etc. But this would require a secondary step. First refine all
found peaks/reflection with a common profile. Then determine the lattice
parameters from the refined peak positions etc.
This is also troublesome as without prior structure "knowledge" it may and
surely is that certain reflection which in fact are overlapping multiple
reflections are improperly identified as "one" reflection.
This is very the neatness of the Rietveld approach comes into play, as it
generates even overlapping reflections which then generate the total
profile by constraining them with the profile parameters.

So the main point in differentiation is then in my eyes:
Rietveld-Refinement: The use of a structure generated peak list which is
constrained with profile parameters.

Profile-Refinement: Profile refinement can work on individual peaks with NO
structure information at all.

Pawley-Refinement then is logically a little bit of a Hybrid, as the
reflection list is pre-generated from the structure. But the intensities
are just matched to best fit the profile. While in a true Rietveld even the
reflection intensities is always generated from the underlying structure
model applied in the Rietveld refinement.

What do you think of this point of view? Am I overlooking something?

Best regards

Stefan Seidlmayer



Am Di., 16. Jan. 2024 um 15:23 Uhr schrieb Alan W Hewat <
alan.he...@neutronoptics.com>:

> Ha ! When Terry Sabine proposed to call it Rietveld Refinement, I told him
> that Rietveld was already "refined".
>
> 
> Dr Alan Hewat, NeutronOptics
> Grenoble, FRANCE (from phone)
> alan.he...@neutronoptics.com
> +33.476984168 VAT:FR79499450856
> http://NeutronOptics.com/hewat
> ___
>
>
> On Tue, 16 Jan 2024, 15:11 ,  wrote:
>
>> Dear all,
>>
>> I'm following this interesting discussion. It seems to me that sometimes
>> there is an improper use of terminology, in particular when we talk
>> about "profile refinement"; in reality, we all know that it is about
>> "profile fitting". Or did I miss something?
>>
>> sorry for the pedantry.
>> Alberto
>> ++
>> Please do NOT attach files to the whole list > >
>> Send commands to  eg: HELP as the subject with no body
>> text
>> The Rietveld_L list archive is on
>> http://www.mail-archive.com/rietveld_l@ill.fr/
>> ++
>>
>> ++
> Please do NOT attach files to the whole list  >
> Send commands to  eg: HELP as the subject with no body
> text
> The Rietveld_L list archive is on
> http://www.mail-archive.com/rietveld_l@ill.fr/
> ++
>
>
++
Please do NOT attach files to the whole list 
Send commands to  eg: HELP as the subject with no body text
The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/
++

Re: Misconduct

[Alan W Hewat]

Ha ! When Terry Sabine proposed to call it Rietveld Refinement, I told him
that Rietveld was already "refined".


Dr Alan Hewat, NeutronOptics
Grenoble, FRANCE (from phone)
alan.he...@neutronoptics.com
+33.476984168 VAT:FR79499450856
http://NeutronOptics.com/hewat
___


On Tue, 16 Jan 2024, 15:11 ,  wrote:

> Dear all,
>
> I'm following this interesting discussion. It seems to me that sometimes
> there is an improper use of terminology, in particular when we talk
> about "profile refinement"; in reality, we all know that it is about
> "profile fitting". Or did I miss something?
>
> sorry for the pedantry.
> Alberto
> ++
> Please do NOT attach files to the whole list  >
> Send commands to  eg: HELP as the subject with no body
> text
> The Rietveld_L list archive is on
> http://www.mail-archive.com/rietveld_l@ill.fr/
> ++
>
>
++
Please do NOT attach files to the whole list 
Send commands to  eg: HELP as the subject with no body text
The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/
++

[SUSPECTED SPAM] Re: Misconduct

[alberto . martinelli]

Dear all,

I'm following this interesting discussion. It seems to me that sometimes 
there is an improper use of terminology, in particular when we talk 
about "profile refinement"; in reality, we all know that it is about 
"profile fitting". Or did I miss something?


sorry for the pedantry.
Alberto
++
Please do NOT attach files to the whole list 
Send commands to  eg: HELP as the subject with no body text
The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/
++

Re: Misconduct

[Reinhard Kleeberg]

Hi Alan,
in general, I could agree your strict definition, reducing the term  
"structure refinement" to atomic coordinates as the main goal.
Hm, "QPA profile refinement" sounds a bit diffuse. What about "QPA  
full pattern profile refinement", resp. "QPA whole powder pattern  
refinement"? Just to include any peak shifting models (e.g. lattice  
parameters), the Fhkl lists, and to separate from single line profile  
fitting methods? Will give an impressive abbreviation in any papers...  
;-)
However, as long as the QPA people are (mis?)using the same software  
tools as the true crystal structure research community, and as long as  
such software was generally put into the "Rietveld" box, I don't  
believe that a more precise terminology for this approach will finally  
have any chance in practical use. Even if the IUCr would redefine the  
terminology and would be able to keep it strictly consistent in their  
own journals: The method was so widely introduced in other fields and  
industries in the last decades under the "Rietveld" label that there  
will be no way back to the roots.

Best regards

Reinhard

Zitat von Alan W Hewat :


Dear Kurt. No, refining just cell parameters doesn't qualify as Rietveld
refinement :-) Certainly Hill/Howard (1987) and Bish/Howard made important
contributions to QPA, but there were earlier papers eg *Werner et al
(1979) * https://scripts.iucr.org/cgi-bin/paper?a18098 that you might also
reference
*"Quantitative analysis of multicomponent powders by full-profile
refinement of Guinier-Hägg X-ray film data"*
So call it QPA Profile Refinement or something similar.

The revolution of Rietveld Refinement was to refine structural parameters
directly to fit the measured profile data. That broke with a long
crystallographic "belief" that it was necessary to first determine
"structure factors" (Bragg intensities), requiring many more parameters,
with their correlations. Attributing all profile refinement to Rietveld, is
not correct, and hides the importance of Rietveld Refinement, which was
hotly contested and not generally accepted by the wider x-ray
crystallographic community for 10+ years
Sakata and Cooper (1979) An analysis of the Rietveld refinement method
https://scripts.iucr.org/cgi-bin/paper?a18236
Without wanting to start another argument, look at the van Laar and Schenk
historical reference list, even if you don't accept their interpretation.
https://journals.iucr.org/a/issues/2018/02/00/ib5058/#BB29

Alan

Dr Alan Hewat, NeutronOptics
Grenoble, FRANCE (from phone)
alan.he...@neutronoptics.com
+33.476984168 VAT:FR79499450856
http://NeutronOptics.com/hewat
___


On Tue, 16 Jan 2024, 09:34 Reinhard Kleeberg, <
kleeb...@mineral.tu-freiberg.de> wrote:


What is Rietveld refinement? Does "Rietveld" QPA exist?
Hill & Howard (1987) titled "QPA from Neutron Powder Diffraction Data
Using the Rietveld Method" and indeed they refined all structural
parameters of their simple phases in binary mixtures, a methodical
test of the approach.

However, the primary goal in QPA "refinement" is to reach an
acceptable fit without running into wrong scale factors. Therefore,
peak positions, profile shapes and all structural factors potentially
biasing the scale factors must be either refined or known previously.
If everything is known, just scale factors must be "refined", may be
by a linear optimization (published since the 1980ies for experimental
patterns), no "Rietveld" code is necessary.
IMHO such simple approach can work well only under very fortunate and
simple/well known circumstances.
However, in routine QPA especially of geological materials of unknown
origin (minerals with not always exactly known chemistry and
microstructure) we typically need to optimize, begining from any
published and selected structure models
- lattice parameters (always)
- profile parameters (always), often with complicated profile models
due to disorder, anisotropic line broadening, bimodal size/microstrain
distribution etc.
- most intensity relevant site occupation (Mg-Fe substitution, K
content of interlayers in micas...), sometimes constrained to lattice
parameters
- PO correction models (if necessary).
As commonly the atomic positions of minerals are often well known from
single crystal work and small deviations do not have a significant
impact on the total scale factors, the atomic coordinates are
typically fixed in QPA. As Debye-Waller factors are hard to refine
from diffraction patterns with limited angular range and for minor
components, it is necessary to fix them in routine work. This means
they must be known exactly (literature?, refined separately (if pure
material is available), or estimated.

So Alan, is the refinement of one site occupation factor in a QPA by
using a Rietveld software enough "structure" to label such analysis as
"Rietveld QPA"? Or, is refining cell parameters an acceptable criterion?
If not, any idea for a better 

Re: Misconduct

[Alan W Hewat]

Dear Kurt. No, refining just cell parameters doesn't qualify as Rietveld
refinement :-) Certainly Hill/Howard (1987) and Bish/Howard made important
contributions to QPA, but there were earlier papers eg *Werner et al
(1979) * https://scripts.iucr.org/cgi-bin/paper?a18098 that you might also
reference
*"Quantitative analysis of multicomponent powders by full-profile
refinement of Guinier-Hägg X-ray film data"*
So call it QPA Profile Refinement or something similar.

The revolution of Rietveld Refinement was to refine structural parameters
directly to fit the measured profile data. That broke with a long
crystallographic "belief" that it was necessary to first determine
"structure factors" (Bragg intensities), requiring many more parameters,
with their correlations. Attributing all profile refinement to Rietveld, is
not correct, and hides the importance of Rietveld Refinement, which was
hotly contested and not generally accepted by the wider x-ray
crystallographic community for 10+ years
Sakata and Cooper (1979) An analysis of the Rietveld refinement method
https://scripts.iucr.org/cgi-bin/paper?a18236
Without wanting to start another argument, look at the van Laar and Schenk
historical reference list, even if you don't accept their interpretation.
https://journals.iucr.org/a/issues/2018/02/00/ib5058/#BB29

Alan

Dr Alan Hewat, NeutronOptics
Grenoble, FRANCE (from phone)
alan.he...@neutronoptics.com
+33.476984168 VAT:FR79499450856
http://NeutronOptics.com/hewat
___


On Tue, 16 Jan 2024, 09:34 Reinhard Kleeberg, <
kleeb...@mineral.tu-freiberg.de> wrote:

> What is Rietveld refinement? Does "Rietveld" QPA exist?
> Hill & Howard (1987) titled "QPA from Neutron Powder Diffraction Data
> Using the Rietveld Method" and indeed they refined all structural
> parameters of their simple phases in binary mixtures, a methodical
> test of the approach.
>
> However, the primary goal in QPA "refinement" is to reach an
> acceptable fit without running into wrong scale factors. Therefore,
> peak positions, profile shapes and all structural factors potentially
> biasing the scale factors must be either refined or known previously.
> If everything is known, just scale factors must be "refined", may be
> by a linear optimization (published since the 1980ies for experimental
> patterns), no "Rietveld" code is necessary.
> IMHO such simple approach can work well only under very fortunate and
> simple/well known circumstances.
> However, in routine QPA especially of geological materials of unknown
> origin (minerals with not always exactly known chemistry and
> microstructure) we typically need to optimize, begining from any
> published and selected structure models
> - lattice parameters (always)
> - profile parameters (always), often with complicated profile models
> due to disorder, anisotropic line broadening, bimodal size/microstrain
> distribution etc.
> - most intensity relevant site occupation (Mg-Fe substitution, K
> content of interlayers in micas...), sometimes constrained to lattice
> parameters
> - PO correction models (if necessary).
> As commonly the atomic positions of minerals are often well known from
> single crystal work and small deviations do not have a significant
> impact on the total scale factors, the atomic coordinates are
> typically fixed in QPA. As Debye-Waller factors are hard to refine
> from diffraction patterns with limited angular range and for minor
> components, it is necessary to fix them in routine work. This means
> they must be known exactly (literature?, refined separately (if pure
> material is available), or estimated.
>
> So Alan, is the refinement of one site occupation factor in a QPA by
> using a Rietveld software enough "structure" to label such analysis as
> "Rietveld QPA"? Or, is refining cell parameters an acceptable criterion?
> If not, any idea for a better name?
>
> Greetings
>
> Reinhard
>
>
> Zitat von Alan W Hewat :
>
> > Yes, it's Rietveld Refinement if you refine the atomic structure
> > parameters. If you define the Rietveld method as simply the calculation
> of
> > the powder pattern, that applies to just about any powder diffraction
> > study, and under values the importance of the method.
> >
> > But you shouldn't refine structure parameters just to get a better fit in
> > QPA by Powder Profile Refinement. I don't know how often you find
> entirely
> > new compounds in QPA, and can determine their structure well enough to
> > publish them as new compounds.
> >
> > The R-factor in this study is impressively low, but it is meaningless as
> > Armel has shown.
> >
> > 
> > Dr Alan Hewat, NeutronOptics
> > Grenoble, FRANCE (from phone)
> > alan.he...@neutronoptics.com
> > +33.476984168 VAT:FR79499450856
> > http://NeutronOptics.com/hewat
> > ___
> >
> >
> > On Mon, 15 Jan 2024, 18:01 Kurt Leinenweber,  wrote:
> >
> >> Hi, in our work we still sometimes 

Re: Misconduct

[Reinhard Kleeberg]

What is Rietveld refinement? Does "Rietveld" QPA exist?
Hill & Howard (1987) titled "QPA from Neutron Powder Diffraction Data  
Using the Rietveld Method" and indeed they refined all structural  
parameters of their simple phases in binary mixtures, a methodical  
test of the approach.


However, the primary goal in QPA "refinement" is to reach an  
acceptable fit without running into wrong scale factors. Therefore,  
peak positions, profile shapes and all structural factors potentially  
biasing the scale factors must be either refined or known previously.  
If everything is known, just scale factors must be "refined", may be  
by a linear optimization (published since the 1980ies for experimental  
patterns), no "Rietveld" code is necessary.
IMHO such simple approach can work well only under very fortunate and  
simple/well known circumstances.
However, in routine QPA especially of geological materials of unknown  
origin (minerals with not always exactly known chemistry and  
microstructure) we typically need to optimize, begining from any  
published and selected structure models

- lattice parameters (always)
- profile parameters (always), often with complicated profile models  
due to disorder, anisotropic line broadening, bimodal size/microstrain  
distribution etc.
- most intensity relevant site occupation (Mg-Fe substitution, K  
content of interlayers in micas...), sometimes constrained to lattice  
parameters

- PO correction models (if necessary).
As commonly the atomic positions of minerals are often well known from  
single crystal work and small deviations do not have a significant  
impact on the total scale factors, the atomic coordinates are  
typically fixed in QPA. As Debye-Waller factors are hard to refine  
from diffraction patterns with limited angular range and for minor  
components, it is necessary to fix them in routine work. This means  
they must be known exactly (literature?, refined separately (if pure  
material is available), or estimated.


So Alan, is the refinement of one site occupation factor in a QPA by  
using a Rietveld software enough "structure" to label such analysis as  
"Rietveld QPA"? Or, is refining cell parameters an acceptable criterion?

If not, any idea for a better name?

Greetings

Reinhard


Zitat von Alan W Hewat :


Yes, it's Rietveld Refinement if you refine the atomic structure
parameters. If you define the Rietveld method as simply the calculation of
the powder pattern, that applies to just about any powder diffraction
study, and under values the importance of the method.

But you shouldn't refine structure parameters just to get a better fit in
QPA by Powder Profile Refinement. I don't know how often you find entirely
new compounds in QPA, and can determine their structure well enough to
publish them as new compounds.

The R-factor in this study is impressively low, but it is meaningless as
Armel has shown.


Dr Alan Hewat, NeutronOptics
Grenoble, FRANCE (from phone)
alan.he...@neutronoptics.com
+33.476984168 VAT:FR79499450856
http://NeutronOptics.com/hewat
___


On Mon, 15 Jan 2024, 18:01 Kurt Leinenweber,  wrote:


Hi, in our work we still sometimes encounter entirely new compounds with
simple structures like rocksalt, spinel, etc.  in order to convince
ourselves and our readers that the materials are real, we have to fit the
powder patterns - put in the atoms, refine lattice parameter(s), show that
thermal parameters are reasonable, fit the peak shapes, background etc all
together.  In the case of spinels for example we can also refine the single
atomic parameter and show that the bond lengths are reasonable.  The
refinements are used to decide whether sites are fully occupied and to
decide the valence of the cation when multiple valence states are possible.
It’s not the kind of thing that would get people really excited with the
crystallographic methods, but it is necessary for convincing ourselves and
others that the identification of the compound is reasonable.  Is that
Rietveld refinement?  I don’t know so I call upon the list to say.

Kurt

Get Outlook for iOS 
--
*From:* rietveld_l-requ...@ill.fr  on behalf
of Matthew Rowles 
*Sent:* Sunday, January 14, 2024 11:04:25 PM
*To:* Alan W Hewat 
*Cc:* Le Bail Armel ; Rietveld_L <
Rietveld_L@ill.fr>
*Subject:* Re: Misconduct

I see the core contribution of the Rietveld method as the point-wise
calculation of a powder pattern. This then enables the refinement of the
parameters.

Yes, attributing QPA to Rietveld is incorrect; that is mainly due to
Hill/Howard and Bish/Howard - I try to make it a point to differentiate
this.

calling PDF refinements Rietveld refinements is just plain wrong (afaik),
unless you actually are moving crystallographic parameters around, in which
case, the nomenclature gets fuzzy..

On Sat, 13 Jan 2024 at 14:39, Alan W Hewat 
wrote:

The core of Rietveld