[Wien] error in lapw0

[Igor Djerdj]

Dear Peter,
I did, I uesd suggestions from setrmt, however the problem is that I have 3 
non-equivalent oxygen, one of them is in the vast channel formed by chains 
of VO6 octahedra. The hydrogen forms O-H bond of length of 0.96A as deduced 
from neutrons diffraction. If I leave it automatically, then gmin>gmax, i.e. 
it is very sensitive to RMT of O2 and H. Should I try to increase Rmax or 
something else?
Regards,
Igor

----- Original Message ----- 
From: "Peter Blaha" <pblaha at theochem.tuwien.ac.at>
To: "A Mailing list for WIEN2k users" <wien at zeus.theochem.tuwien.ac.at>
Sent: Tuesday, June 05, 2007 9:04 AM
Subject: Re: [Wien] error in lapw0


> Why don't you use the suggestions from setrmt during initialization (or 
> first
> point in structgen/w2web) ?
>
> a) All Radii of a particular atom must be the same. So choose ALL Oxygen
> spheres the same.
> b) H spheres should be "half" as big as their partners. So with a O2-H 
> distance
> near 1.7 bohr choose 1.15 and 0.55 (or similar).
>
> Then run a "complete" initialization!! Don't "skip" certain steps (like
> dstart), otherwise case.in0 might not be correct and you get your error in 
> lapw0
>
> Igor Djerdj schrieb:
>>
>>
>> Dear all,
>>  I am trying to perform calculation on the system which comprises V, O
>> and H.  I took into account tips and tricks which are written in the
>> manual or faq regarding Rmax =3 or 4, Gmax up to 25, and I adjusted RMT
>> in order to get gmin<gmax. The latter condition is fullfiled if I choose
>> for RMTs:
>> V 1.77
>> O1 1.12
>> O2 0.89
>> O3 1.12
>> H  0.8.
>> H is attached to O2. Especially, RMt of H and O2 are very sensitive to
>> condition gmin<gmax. Then I run scf and meet after 1 cycle with the
>> error in lapw0:
>> IFFT TOO SMALL IN XCPOT3
>> 2*(KKK+1) LARGER THAN IFFT PARAMETER IN XCPOT3
>> KKK  0 54 0
>>         0 54 0
>> IFFT 108 108 80.
>> What should I do?
>> Regards,
>> Igor
>>
>>
>>
>>
>>
>> ------------------------------------------------------------------------
>>
>> _______________________________________________
>> Wien mailing list
>> Wien at zeus.theochem.tuwien.ac.at
>> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
>
> -- 
>
>                                       P.Blaha
> --------------------------------------------------------------------------
> Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
> Phone: +43-1-58801-15671             FAX: +43-1-58801-15698
> Email: blaha at theochem.tuwien.ac.at    WWW: 
> http://info.tuwien.ac.at/theochem/
> --------------------------------------------------------------------------
> _______________________________________________
> Wien mailing list
> Wien at zeus.theochem.tuwien.ac.at
> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien