[Wien] Req. info. about case.inso for BiFeO3

[Dr. K. Balamurugan]

Dear Wien2k developers/users,

I am performing LSDA+U+SO calculation for a system related to BiFeO3.
I could go up to LSDA+U and get my SCF converged both for cc and ec.
Now, to add Spin-Orbit coupling, I get doubts about setting up the
case.inso file: for which elements I shall add p1/2 LO? What value I
shall choose to give for Eparam (or El)? etc...

I am not able gain enough knowledge from the Wien2k user guide. Is
there any other knowledge resources on that matter?

If anyone had already performed such SO calculation for BiFeO3, please
share the case.inso file and suggest me any material to refer for
selecting energy values etc.

Thanks.

With regards
K. Balamurugan,
NIT Trichy, India.

[Dr. K. Balamurugan]

Thanks to Prof. Peter Blaha and Prof. Gavin Abo.

I have tried both your suggestions; besides expecting them to work for
me, I faced another problem. After setting up the case.inso file, a
run of "xsymmetso" showed the following:
================================================================
gamma not equal 90
gamma not equal 90
ERROR: negative position in rstruc. Please report
================================================================

I tried to understand what it is and how to get out of these by
exploring old email conversations; but, I found nearly no perfect
help. Please, someone clarify me about this warning/error message.

Thanks

With regards
K. Balamurugan
NIT Trichirappalli.

Bi does not have semicore p states.
So usage of p1/2 LOs is not necessary.

Post by Dr. K. Balamurugan
Dear Wien2k developers/users,
I am performing LSDA+U+SO calculation for a system related to
BiFeO3. I could go up to LSDA+U and get my SCF converged both for
cc and ec. Now, to add Spin-Orbit coupling, I get doubts about
setting up the case.inso file: for which elements I shall add p1/2
LO? What value I shall choose to give for Eparam (or El)? etc...
I am not able gain enough knowledge from the Wien2k user guide. Is
there any other knowledge resources on that matter?
If anyone had already performed such SO calculation for BiFeO3,
please share the case.inso file and suggest me any material to
refer for selecting energy values etc.
Thanks.
With regards
K. Balamurugan,
NIT Trichy, India.
_______________________________________________
Wien mailing list
http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien

--
P.Blaha
--------------------------------------------------------------------------
Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
Phone: [phone] FAX: [phone]
WWW: http://www.imc.tuwien.ac.at/TC_Blaha
--------------------------------------------------------------------------
_______________________________________________
Wien mailing list
http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien

[Gavin Abo]

"ERROR: negative position in rstruc" is typically because there is
something wrong with case.struct file [1].

It commonly happens with hexagonal lattices [2,3].  The cause is
typically a precision or rounding issue [4,5].

"x patchsymm" can sometimes be used to fix the problem [6].

In WIEN2k 18.2, low tolerance values (tol=1.e-4) are used for
symmetry/symmetso.  It may be that you have a unique structure that
leads to problems (it may be that it can be resolved with a higher
tol=1.e-3) [7].

It is likely that nobody can help further unless you provide the
case.struct file.

[1]
https://www.mail-archive.com/***@zeus.theochem.tuwien.ac.at/msg09907.html
[2]
https://www.mail-archive.com/***@zeus.theochem.tuwien.ac.at/msg06519.html
[3]
https://www.mail-archive.com/***@zeus.theochem.tuwien.ac.at/msg07362.html
[4]
https://www.mail-archive.com/***@zeus.theochem.tuwien.ac.at/msg16621.html
[5]
https://www.mail-archive.com/***@zeus.theochem.tuwien.ac.at/msg07074.html
[6]
https://www.mail-archive.com/***@zeus.theochem.tuwien.ac.at/msg07063.html
[7]

Post by Dr. K. Balamurugan
Thanks to Prof. Peter Blaha and Prof. Gavin Abo.
I have tried both your suggestions; besides expecting them to work for
me, I faced another problem. After setting up the case.inso file, a
================================================================
 gamma not equal 90
 gamma not equal 90
ERROR: negative position in rstruc. Please report
================================================================
I tried to understand what it is and how to get out of these by
exploring old email conversations; but, I found nearly no perfect
help. Please, someone clarify me about this warning/error message.
Thanks
With regards
K. Balamurugan
NIT Trichirappalli.

[Dr. K. Balamurugan]

My sincere thanks for further helps.

After I changed "H" for "P", the following did NOT appear:

================================================================
gamma not equal 90
gamma not equal 90
ERROR: negative position in rstruc. Please report
================================================================

Now, the calculation goes well.

Thanks.

With kind regards
K. Balamurugan,
NIT Tiruchirappalli

Post by Gavin Abo
"ERROR: negative position in rstruc" is typically because there is
something wrong with case.struct file [1].
It commonly happens with hexagonal lattices [2,3].  The cause is
typically a precision or rounding issue [4,5].
"x patchsymm" can sometimes be used to fix the problem [6].
In WIEN2k 18.2, low tolerance values (tol=1.e-4) are used for
symmetry/symmetso.  It may be that you have a unique structure that
leads to problems (it may be that it can be resolved with a higher
tol=1.e-3) [7].
It is likely that nobody can help further unless you provide the
case.struct file.
[1]
[2]
[3]
[4]
[5]
[6]
[7]

Post by Dr. K. Balamurugan
Thanks to Prof. Peter Blaha and Prof. Gavin Abo.
I have tried both your suggestions; besides expecting them to work
for me, I faced another problem. After setting up the case.inso
================================================================
 gamma not equal 90
 gamma not equal 90
ERROR: negative position in rstruc. Please report
================================================================
I tried to understand what it is and how to get out of these by
exploring old email conversations; but, I found nearly no perfect
help. Please, someone clarify me about this warning/error message.
Thanks
With regards
K. Balamurugan
NIT Trichirappalli.

_______________________________________________
Wien mailing list
http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien