unitcell optimization with exact exchange
Posted: Tue Sep 06, 2011 8:01 pm
Hi, I am calculating V2O5 unit-cell using screened exchange (EECE).
For an optimized structure, I am running as:
1. ionmov = 2, optcell=0
After convergence,
2. ionmov = 2, optcell=2
Without EECE, abinit predict the unit-cell close to experimental data. But when EECE option is on,
unit-cell volume increases very high, yielding non-physical size (1.25e3 -> 1.5e3 or even larger).
Is there any option to constrain volume increase rate? Or any comment will be very appreciated.
ByoungSeon
For an optimized structure, I am running as:
1. ionmov = 2, optcell=0
After convergence,
2. ionmov = 2, optcell=2
Without EECE, abinit predict the unit-cell close to experimental data. But when EECE option is on,
unit-cell volume increases very high, yielding non-physical size (1.25e3 -> 1.5e3 or even larger).
Is there any option to constrain volume increase rate? Or any comment will be very appreciated.
ByoungSeon