## wrong order of eigenvalues with GW

Questions of type &quot;How do I calculate xxx ?&quot;
(Open discussion, limited support from the helpdesk.)

Moderators: Moderator, Global Moderator

### wrong order of eigenvalues with GW

Hello,

What's the reason for the wrong order of eigenvalues in GW calculations? See for example in the EIGENVAL file:

87 -2.590373 1.000000
88 -1.771691 1.000000
89 -2.332173 1.000000
90 -2.332173 1.000000
91 -2.332173 1.000000
92 -2.388984 1.000000
93 -2.388984 1.000000
94 -1.562871 1.000000
95 4.932852 0.000000
96 5.400439 0.000000
97 5.400439 0.000000
98 5.644009 0.000000
99 5.644009 0.000000
100 5.644009 0.000000
101 4.402456 0.000000
102 5.761689 0.000000
103 5.761689 0.000000

And my INCAR is:

SYSTEM = st
ENCUT = 500 eV
PREC = Accuracy
LREAL = FALSE
GGA = PE

# electron
ISMEAR = 0
SIGMA = 0.05
EDIFF = 1.e-8

ALGO = GW0
NELM = 1
NBANDS = 2400

ENCUTGW = 100
NOMEGA = 200
PRECFOCK = Fast
LWAVE = F

Best,

Xiaoming Wang
wxiaom86
Newbie

Posts: 16
Joined: Sun Jan 29, 2017 4:10 am

### Re: wrong order of eigenvalues with GW

please do a final sub-space diagonalization
LDIAG = .True.
to order the eigenvalues

Posts: 2911
Joined: Tue Aug 03, 2004 8:18 am

### Re: wrong order of eigenvalues with GW

LDIAG = .True.
to order the eigenvalues

Do you mean that I need put 'LDIAG = .TRUE.' in my INCAR? I checked the OUTCAR of my GW calculation, LDIAG = .True. is the default setup.

I also tried to read the GW WAVECAR with ALGO = Eigenval or Subrot and LDIAG = True and NELM = 1. This would however give the DFT energies.

Best,
Xiaoming Wang
wxiaom86
Newbie

Posts: 16
Joined: Sun Jan 29, 2017 4:10 am