# [Wien] A possible bug in abclm.f (of LAPWSO)

Guo-ping Zhang gpzhang at femto.indstate.edu
Mon Dec 19 15:50:46 CET 2011

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Thanks a lot, Peter!

It is true that they are same for several years, but it is different from
WIEN97 version. I also printed out k+G vectors and found the current
abclm.f and hamilt.F produce different results. When k+G vectors are input
into hamilt.F, they are already multiplied by b vectors, but when k+G
is input into abclm.f they are not. Since alm and blm must be same in
lapwso and lapw1, then one of the above treatments must be incorrect.

Best regards,
Guopig

On Mon, 19 Dec 2011, Peter Blaha wrote:

> Hi,
>
> I checked my sources. This subroutine has not changed for several years and
> furthermore it
> looks exactly as you showed in your mail, which I believe is correct.
>
> Regards
>
> Am 14.12.2011 16:19, schrieb Guo-ping Zhang:
>> Dear Peter,
>>
>> I noticed a possible error in abclm.f. The old wien is correct, but the new
>> one is not. See below. The rotation matrix should be applied only after G
>> vectors multiplied by unit
>> vectors b1,b2,b3. I compared this with hamilt.F where my code can reproduce
>> your results with accuracy up to 10^-13.
>>
>> BK(1)=BKX(I)
>> BK(2)=BKY(I)
>> BK(3)=BKZ(I)
>> CALL ROTATE (BK,ROTIJ(1,1,indj),BKROT)
>> BK(1)=BKROT(1)*BR1(1,1)+BKROT(2)*BR1(1,2)+BKROT(3)*BR1(1,3)
>> BK(2)=BKROT(1)*BR1(2,1)+BKROT(2)*BR1(2,2)+BKROT(3)*BR1(2,3)
>> BK(3)=BKROT(1)*BR1(3,1)+BKROT(2)*BR1(3,2)+BKROT(3)*BR1(3,3)
>> CALL ROTATE (BK,ROTLOC(1,1,JA),BKRLOC)
>> CALL YLM(BKRLOC,LABC,YL)
>>
>> Thanks a lot!
>>
>> Guoping
>> _______________________________________________
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>
> --
>
>                                      P.Blaha
> --------------------------------------------------------------------------
> Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
> Phone: +43-1-58801-165300             FAX: +43-1-58801-165982
> Email: blaha at theochem.tuwien.ac.at    WWW: http://info.tuwien.ac.at/theochem/
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