[Wien] Symmetry for lapw1c in LDA+U

[Peter Blaha]

When adding SO AND orb; the latter is added in lapwso, which is 
"complex" anyway.

Still you have the symmetry which is compatible with a) your crystal 
symmetry, and b) with the SO interaction (direction of magnetization).

There are cases (mainly rare-earth compounds), where you may want to 
reduce the symmetry further (to get a "localized, atomic-like state", 
which does not obey crystal symmetry. But this requires that you 
"understand" the symmetries and their consequences (degeneracy of states).


D.A. Tompsett schrieb:
> Dear All,
>         I am using the latest WIEN2k_08.2 release on a unix platform.
> 
> I am attempting to calculate the eigenvalues for my system in the full
> Brillouin zone. I wish to do so using LDA+U with S-O coupling.
> 
> I am running the execution commands in the following sequence as 
> recommended so that I may ramp up the U slowly: runsp_lapw save_lapw case 
> initso_lapw runsp_lapw -so save_lapw case runsp_lapw -so -orb
> 
> The question I have relates to a phrase in the UG on p.83 under the ORB 
> function: "The presence of such an orbital field may lower the symmetry. In 
> particular the complex version of LAPW1 must be used."
> 
> My question is, if the symmetry is lowered by the orbital field will the 
> code automatically detect this and run lapw1c? In my case.dayfile this is 
> not occuring for the -orb run:
>     cycle 1 	(Mon Aug 18 18:15:55 BST 2008) 	(40/99 to go)
> 
>>   lapw0 	(18:15:55) 4.580u 0.420s 0:06.08 82.2%	0+0k 0+0io 182pf+0w
>>   orb -up 	(18:16:01) 0.000u 0.000s 0:01.14 0.0%	0+0k 0+0io 98pf+0w
>>   orb -dn 	(18:16:03) 0.010u 0.010s 0:00.08 25.0%	0+0k 0+0io 0pf+0w
>>   lapw1 -up (18:16:03) 352.730u 7.760s 6:02.01 99.5% 0+0k 0+0io 302pf+0w
>>   lapw1  -dn  	(18:22:05) 352.650u 7.660s 6:00.82 99.8%	0+0k 0+0io 0pf+0w
>>   lapwso -up -orb (18:28:06) 177.240u 5.500s 3:05.50 98.5% 0+0k 0+0io 
>> 266pf+0w
>>   lapw2 -c -up -so (18:31:11) 115.440u 3.340s 2:01.17 98.0% 0+0k 0+0io 
>> 239pf+0w
>>   lapw2 -c -dn -so (18:33:13) 115.430u 3.500s 1:59.11 99.8% 0+0k 0+0io 
>> 0pf+0w
>>   lapwdm -up -so -c (18:35:12) 5.250u 0.620s 0:07.51 78.1% 0+0k 0+0io 
>> 158pf+0w
>>   lcore -up	(18:35:19) 0.050u 0.090s 0:01.60 8.7%	0+0k 0+0io 95pf+0w
>>   lcore -dn	(18:35:21) 0.060u 0.080s 0:00.45 31.1%	0+0k 0+0io 0pf+0w
>>   mixer 	(18:35:22) 0.360u 0.410s 0:02.45 31.4%	0+0k 0+0io 139pf+0w
> :ENERGY convergence:  0 0.0001 0
> :CHARGE convergence:  0 0.0000 0
> 
> Otherwise how do I know if I need to direct lapw1c to run and how would I 
> do it?
> 
> Thank you,
> David Tompsett
> Quantum Matter Group
> Cavendish Laboratory
> J. J. Thomson Avenue
> Cambridge CB3 0HE
> U.K.
> Tel: +44 7907 566351 (mobile)
> Fax: +44 1223 337351
> http://www-qm.phy.cam.ac.uk/
> 
> 
> 
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> Wien mailing list
> Wien at zeus.theochem.tuwien.ac.at
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-- 
-----------------------------------------
Peter Blaha
Inst. Materials Chemistry, TU Vienna
Getreidemarkt 9, A-1060 Vienna, Austria
Tel: +43-1-5880115671
Fax: +43-1-5880115698
email: pblaha at theochem.tuwien.ac.at
-----------------------------------------