Strange ICHARG=11 Vs ICHARG=1 behavior
Posted: Fri Jul 20, 2007 11:23 am
For a test we have done a single point (spin polarized GGA+U) optimization for an insulator using first ICHARG=1 creating a WAVECAR and CHGCAR, that are used next into a non self-consistent run (ICHARG=11) with exactly all the same other parameters as presented below
PREC = Accurate
LREAL=A
ALGO = VeryFast
ISPIN = 2
NELMIN = 5
EDIFF = 5E-06
ENCUT = 600
ISYM = 0
LORBIT = 11
NEDOS = 600
ISTART=1
ICHARG=1
Ionic relaxation
EDIFFG = -5E-2
ISIF = 3
NSW = 0
IBRION = -1
MAGMOM = 5 -5 10*0 16*0 10*0
LDAU=.TRUE.
LDAUTYPE = 1
LDAUL=2 -1 -1 -1
LDAUU=5.0 0 0 0
LDAUJ=1.0 0 0 0
DOS related values
ISMEAR = -5
calcul parallele
LPLANE=.TRUE.
NPAR=4
LSCALU=.FALSE.
NSIM=4
We are surprise NOT to get the exact same energy (by 0.196 eV) and a different relative position of the KS states
I would have expected to get the SAME energy and DOS for both calculations as in the non-self constistant run we are using the optimized self consistant charge and starting with the self consistant wave function. We have check that the chosen smearing energy has no effect (as expected for an isulator)
Are we missing something ?
Thanks for your help
PREC = Accurate
LREAL=A
ALGO = VeryFast
ISPIN = 2
NELMIN = 5
EDIFF = 5E-06
ENCUT = 600
ISYM = 0
LORBIT = 11
NEDOS = 600
ISTART=1
ICHARG=1
Ionic relaxation
EDIFFG = -5E-2
ISIF = 3
NSW = 0
IBRION = -1
MAGMOM = 5 -5 10*0 16*0 10*0
LDAU=.TRUE.
LDAUTYPE = 1
LDAUL=2 -1 -1 -1
LDAUU=5.0 0 0 0
LDAUJ=1.0 0 0 0
DOS related values
ISMEAR = -5
calcul parallele
LPLANE=.TRUE.
NPAR=4
LSCALU=.FALSE.
NSIM=4
We are surprise NOT to get the exact same energy (by 0.196 eV) and a different relative position of the KS states
I would have expected to get the SAME energy and DOS for both calculations as in the non-self constistant run we are using the optimized self consistant charge and starting with the self consistant wave function. We have check that the chosen smearing energy has no effect (as expected for an isulator)
Are we missing something ?
Thanks for your help