band structure calculation for insulators with strong correlation of metals

Queries about input and output files, running specific calculations, etc.


Moderators: Global Moderator, Moderator

Post Reply
Message
Author
GRYTSYSY
Newbie
Newbie
Posts: 2
Joined: Sun Jun 05, 2011 5:22 pm

band structure calculation for insulators with strong correlation of metals

#1 Post by GRYTSYSY » Sat Jun 25, 2011 5:52 pm

Dear all,

I did Band structure calculation by using LSDA+U method.
But unfortunately I got incorrect result, different from those that are in literature.
Here is my INCAR for SCF:

SYSTEM = (Co O)6 (P1) ~ /home/medea/Desktop/CoO111/CoO.cif, phase System: CoO (VASP)

PREC = Normal

ENCUT = 400.000

IBRION = -1

NSW = 0

NELMIN = 2

EDIFF = 1.0e-05

EDIFFG = -0.02

VOSKOWN = 1

NBLOCK = 1

NELM = 60

ALGO = Normal (blocked Davidson)

ISPIN = 2

MAGMOM = 3 -3 3 -3 3 -3 6*0

LDAU = .TRUE.

LDAUTYPE = 1

LDAUL = 2 -1

LDAUU = 7.1 0

LDAUJ = 1 0

LMAXMIX = 4

LORBIT = 1

ICHARG = 2

INIWAV = 1

ISTART = 0

LWAVE = .TRUE.

LCHARG = .TRUE.

ADDGRID = .FALSE.

ISMEAR = 0

SIGMA = 0.1

LREAL = .FALSE.

RWIGS = 1.16 0.73

NPAR = 8

LPLANE = F



In NSCF I put

ISTART = 1

ICHARG = 11


and used CHG, CHGCAR and WAVECAR files from SCF.

Also, I used Medea for my calculation. Interesting is that when I chose only one option ?Band Structure calculation? I got incorrect result, but when I chose two options ?DOS calculation? and ?Band structure calculation? I got correct result.

Can someone explain me why I got this inconsistency? And what is the best way for doing calculation of band structure for insulators with strong correlation (CoO)?
I suppose that crucially important is ?ISMEAR? option. But for Band structure NSCF calculation we can't use ISMEAR = -5.

thanks a lot
Last edited by GRYTSYSY on Sat Jun 25, 2011 5:52 pm, edited 1 time in total.

boris
Full Member
Full Member
Posts: 106
Joined: Wed Jan 16, 2008 1:27 pm
License Nr.: 567
Location: France

band structure calculation for insulators with strong correlation of metals

#2 Post by boris » Wed Jul 06, 2011 7:40 pm

Hi

Your system is an insulator, so ISMEAR doesn't have any influence (it's for fractional occupancies, i.e. metals). Try using ISMEAR=-5, it's better than a Gaussian smearing.

I don't know about Medea but what kind of inconsistency do you have? It is strange that activating an additional option leads to correct results....

Regards

Boris
Last edited by boris on Wed Jul 06, 2011 7:40 pm, edited 1 time in total.

Post Reply