Negative value in CHGCAR for Si bulk scf calculation
Posted: Tue Jun 01, 2010 3:36 pm
Dear VASP users and head administrator
I have a 2 atom Si in bulk diamond structure. I used VASP5.2 (and
VASP4.6) for self-consistent run and got the CHGCAR file. I checked
the CHGCAR file it has many negative values of total charge density
which is unphysical.
My system is bulk without any vacuum. I checked VASP FAQ's in the manual
but mainly it talks about unphysical negative charge when vacuum is present.
My INCAR file looks like this:
I post 3 different INCAR files showing negative charge in CHGCAR
-1st
ISTART = 0
ICHARG = 2
PREC = medium
ISMEAR = 1
EDIFF = 1E-04 stopping-criterion for ELM
-2nd
ISTART = 0
ICHARG = 2
PREC = medium
ISMEAR = 0
EDIFF = 1E-04 stopping-criterion for ELM
-3rd
ISTART = 0
ICHARG = 2
INIWAV = 1
ISPIN = 1
PREC = high
NELM = 100
NELMIN = 5
EDIFF = 1E-05 stopping-criterion for ELM
ENCUT = 340.0000
ISYM = 0
ADDGRID = T
ISMEAR = -5
IALGO = 48
LREAL = .FALSE.
GGA_COMPAT = .FALSE. #faster calc
SYMPREC = 1E-06 #to remove "found some non integer element in rotn matrix" error
NGXF= 90
NGYF= 90
NGZF= 90
Pl. let me know if any additional info related to this is needed.
--Sahu
I have a 2 atom Si in bulk diamond structure. I used VASP5.2 (and
VASP4.6) for self-consistent run and got the CHGCAR file. I checked
the CHGCAR file it has many negative values of total charge density
which is unphysical.
My system is bulk without any vacuum. I checked VASP FAQ's in the manual
but mainly it talks about unphysical negative charge when vacuum is present.
My INCAR file looks like this:
I post 3 different INCAR files showing negative charge in CHGCAR
-1st
ISTART = 0
ICHARG = 2
PREC = medium
ISMEAR = 1
EDIFF = 1E-04 stopping-criterion for ELM
-2nd
ISTART = 0
ICHARG = 2
PREC = medium
ISMEAR = 0
EDIFF = 1E-04 stopping-criterion for ELM
-3rd
ISTART = 0
ICHARG = 2
INIWAV = 1
ISPIN = 1
PREC = high
NELM = 100
NELMIN = 5
EDIFF = 1E-05 stopping-criterion for ELM
ENCUT = 340.0000
ISYM = 0
ADDGRID = T
ISMEAR = -5
IALGO = 48
LREAL = .FALSE.
GGA_COMPAT = .FALSE. #faster calc
SYMPREC = 1E-06 #to remove "found some non integer element in rotn matrix" error
NGXF= 90
NGYF= 90
NGZF= 90
Pl. let me know if any additional info related to this is needed.
--Sahu