Riccardo,
In looking through the GSAS source, I find that there are two criteria used to
determine if a problem has reached convergence. First all variable groups, such
as lattice constants or atom variables, must have a sum of (esd/shift)**2 of
less than 0.01 and secondly the total sum of all (esd/shift)**2 must be less
than 10**ICNVRG where INCVRG is the number being requested with the 'V' option.
I don't know if the 'V' has been removed in the six years since I turned GSAS
over to Bob Von Dreele or if it never got into the menu, I suspect the latter. I
have modified the menus in the Macintosh version to show the 'V' and added to
the data request a statement intended to indicate that an integer is required as
the data to be changed.
I will admit that I was a bit confused when I tried to enter 0.01 and got told
that there was an error in the string.
Allen C. Larson
Riccardo Vivani wrote:
>
> Dear all,
> in GSAS, L-S control editing option menu appears as follows
> Enter L-S control editing option (<?>,A,B,C,D,E,J,L,P,X) >
>
> By entering "V" (which is not in the list) a new convergence criterion is
> asked:
> Enter the new convergence criterion >
>
> Can I have more information on this, and also the more appropriate answer to
> that question?
> Thank you in advance
>
> Riccardo Vivani
> Laboratiorio di Chimica Inorganica
> Dipartimento di Chimica
> Perugia - Italy
