Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

12.09.2017, 18:48 +04:00 from Abderrahmane Reggad : >Therefore I was satisfied with the study of the 3 configurations (nm, fm and >afmi) to find the afmI phase to be the most stable. Then I do not understand: your "afmi" in fact becomes nonmagnetic, and its energy should be

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

Thank you Gerhard for your advise I read and I understand What do you think if using the empirical parameters known give you calculated values for band gap and magnetic moment ten times or more than the experimental one. Before using my value for alpha parameter, I used the alpha value equal to

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

Did you read and understand Rationale for mixing exact exchange with density functional approximations John P. Perdew, Matthias Ernzerhof, and Kieron Burke The Journal of Chemical Physics 105 , 9982 (1996) or similar articles and references there ? Usually, the parameters of the

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

Hi Lyudmila I have forgotten to add the article link http://www.sciencedirect.com/science/article/pii/S0921452617303915 ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

Hi Martin I still confused and not convinced with my results. It's not the band gap of NiS to take as the only criterion for the choice of the amount of excact exchange, but also the experimental values of magnetic moment. This amount allows me to get magnetic moment values close to the

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

Hi Lyudmila in the following article I studied the 3 different possible orderings for the NiAs structure for the NiS compound and I found that the I-type order is the most stable which is consistent which all theoritical and experimental results. It's found also that all transition metal

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

11.09.2017, 17:24 +04:00 from Abderrahmane Reggad : I have repeated the calculation using ec and cc criterion equal to 0.1 and 0.0001 respectively and I have found the magnetic moment to be lesser with the value of 0.0002 MB. Maybe I missed the point in your discussion

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

Hi, A. Reggad There are no questions in your last posts so the case seems to be closed. However, I am curious, and there seems to be something to learn in addition to the nice comments made by G. Fecher: First, is the band gap (of NiS) really a good observable to fix the HF mixing (for

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

The only point I was making was that you have to be able to justify whatever fraction is used. On Sep 11, 2017 2:55 PM, "Abderrahmane Reggad" wrote: > Hi Laurence > > The amount of 0.05 of exact exchange is the value that gives a gap value > equal to the experimental one for

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

Hi Laurence The amount of 0.05 of exact exchange is the value that gives a gap value equal to the experimental one for nickel sulphide and close values for magnetic moments for some 3d transition metal sulphides like CrS, FeS, CoS and NiS. You can check my article about the nickel sulphide

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

Why are you using 0.05 for the amount of exact exchange? You must justify that this is valid (you, not me). On Sep 11, 2017 2:24 PM, "Abderrahmane Reggad" wrote: > Hi all > > I have repeated the calculation using ec and cc criterion equal to 0.1 > and 0.0001 respectively

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

Hi all I have repeated the calculation using ec and cc criterion equal to 0.1 and 0.0001 respectively and I have found the magnetic moment to be lesser with the value of 0.0002 MB. Here are the input files VS.struct *** VS-hex H LATTICE,NONEQUIV.ATOMS: 3 164_P-3m1 MODE OF

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

Hi Before doing the calculation again with the new energy and charge criterion I let you this old article http://journals.jps.jp/doi/abs/10.1143/JPSJ.14.196 Best regards ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

I would say that -cc 0.001 -ec 0.001 are certainly too large. Also, a more subtle point. When you say you use "-eece" what hybrid fraction? Is that the right fraction? How do you know if it is the right value to use? On Sep 8, 2017 9:13 AM, "Fecher, Gerhard" wrote: > Now I

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

First, as Gavin told, your convergence criteria are too bad to decide about your magnetic moments just try to improve them in steps say up to ec 10^-6 cc 10^-3 and see what happens with the moments (that was why I asked fror it) however be sure you have enough k-points I assume you used the

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

Now I am a little confused do you think that it was the convergence criteria that I found a magnetic moment of 2.5 mu_B instead of 0.05 mu_B at the V ? or did I make another mistake ;-) Indeed, you are right, the 0.05 mu_B might be a result of to bad convergence however, to check if such a

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

Perhaps the -ec 0.001 and -cc 0.001 are too large of values. As I recall, to be well-converged, it is usually best to use about the default values seen in the post [1] or WIEN2k 17.1 usersguide [2] as: -cc 0.0001 -ec 0.0001 It sounded like about the default value for -ec was good unless

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

Your calculations are probably fine. Apologies for my previous posting but my point was partly that I think you said the experimentalists claimed it was Pauli paramagnetic. Pauli paramagnetism is not the type of paramagnetism that arises from unpaired electrons on metal ions in, for example,

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

Hi All I have used the PBE+EECC calculation for 3 configurations: nm, fm and afm I and I found that the afm I is the most stable. The energy criterion and charge are 0.001 Ry and 0.001 e respectively. I don't worry about if the material is really antiferromagnetic or paramagnetic because of:

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

Hi Gerhard 1- The charge criterion was 0.001 e 2- I didn't started from a converged PBE calculation 3- The amount of exact exchange use leads for results consistent with experiment for the other 4 compounds. 5- Geometrical optimization leads to AFM 1 to be the most stable 6- i found only

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

The problem is that I want to know if it's possible to get a such value of 0.05 MB for atomic magnetic moment for the AFM state of vanadium sulphide in NiAs structure. Correct me if I'm wrong, but I believe you are saying that you opened the case.scf file in a text editor or did a "grep -e

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

I agree, there is some confusion. There probably always is. The confusion here is mainly about definition para-, dia-, ferro-, antiferro-, heli-, or non- magnetic. This comes up every now and then. As I said before, I like the following distinction. a) Define Non-Magnetic ONLY in context of

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

I am used to setting up calculations with spins set to be parallel or antiparallel to each other and I would probably class those set up with antiparallel spins as AFM. You can also set up calculations that don't include spin and so will not have any magnetic moments. I tend to regard these as

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

Your problem is 'if it's possible to get' AF VS with 0.05 mu_B/Vanadium in DFT? IF (capitals are on purpose here) you did everything right to properly converge your calculations to the necessary numerical precision, then you give the answer yourself: Yes, it is possible if one uses GGA+U or

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

Sorry but there is obviously a lot of nonsense in the comments where you should first think about: Please explain why a spin polarized calculation will always result in a ferromagnetic (or antiferromagnetic) state ? How do you define a ferromagnet (or antiferromagnet) ? What happens when the

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

I have been following this thread and I think there is some confusion. 1. On the thread it said that the experiment showed it was Pauli paramagnetic. This is the type of magnetism displayed by some metals e.g. sodium which is only apparent if you apply a magnetic field. 2. If you include spin

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

0.05 muB does not mean that it is antiferromagnetic ! what was your charge convergence criterion ? You did never answer my question whether you started the EECE calculation from a converged GGA calculation. Why do you like to have an afm state when the experiment tells it is not ? Ciao

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

Hi Martin The problem is that I want to know if it's possible to get a such value of 0.05 MB for atomic magnetic moment for the AFM state of vanadium sulphide in NiAs structure. Hafner and Hobbs have found all the calculations converged to the non magnetic state because they have used the GGA

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

I took an admittedly brief look at your link, and I still don't understand where your problem really is. I have made calculations for 5 3d transition metal sulphides with the method PBE+EECE and I have found that all the results are ok with the exception of the vanadium sulphide. I have

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

I have made calculations for 5 3d transition metal sulphides with the method PBE+EECE and I have found that all the results are ok with the exception of the vanadium sulphide. I have made 3 calculations (nm, fm and afmI ) to determine the magnetic state for all the compounds and I found them to

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

High A. Reggad, substitute V for Cr in Prof. Fecher's questions, otherwise I am with him. In case you refer by 'almost zero' to the 0.05 mu_B I seem to recall from your original question, and now wonder about some fundamental discrepancy between the supposed experimental Pauli paramagnetism

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

About what moment are you talking, the total magnetic moment or the magnetic moment of the Cr atoms ? Did you start your EECE calculation from a regular GGA calculation that had no magnetic moments at the Cr ? Ciao Gerhard DEEP THOUGHT in D. Adams; Hitchhikers Guide to the Galaxy: "I think

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

Thanks martin Experimentally they found that the vanadium sulphide is a pauli paramagnetic but I have found it to be antiferromagnetic like other transition metal sulphides but the magnetic moment value equals almost zero despite the fact that vanadium has 3 inpaired electrons. Best regards

Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

Be aware that Hund's rules do rest on certain assumptions about the relative strength of intra- and inter-atomic couplings. There are, after all, a lot of para- or diamagnetic materials around. Try to look that up. Is your Vanadium sulphide magnetically ordered from experiment? In your case