and now I got problems on electronic convergence.
When I was doing ionic relaxation,
the electronic relaxation took 141 steps to accuracy of 10^(-4) for the 1st scf loop,
and all subsequent scf loops took only a few steps after movements of ions.
This calculation is done with 15A vacuum (15x20x30 unit cell) at each sides, Tetrahedron method with Blochl correction, 1x3x2 k-points, PAW-GGA PPs.
Code: Select all
!Job
SYSTEM=PTCDA
NWRITE=2
LELF=T
!Electronic
ENCUT= 520 eV
EDIFF= 1E-05
NELM=1000
PREC = high
NBANDS=100
ISMEAR = -5
LORBIT = 12
ISTART=0
ICHARG= 0
LCHARG = TRUE
ISPIN=1
!Ion
ISIF=2
IBRION= 2
NSW = 1000
NBLOCK = 1
KBLOCK = 1
LCORR = T
!Computaion
NSIM = 2
NPAR = 1
LPLANE = TRUE
ALGO = Fast
LREAL = Auto
After the ionic relaxation, I started a series of test for convergence of Energy with respect to ENCUT (from 300 to 520),
then I got convergence problems on electronic relaxations:
only the one with ENCUT=440 converged in 187 steps and all others cannot converge in 1000 steps.
Compared to the previous relaxation calculation, the only difference in INCAR was that PREC was changed to Accurate and ENCUT was changed to values from 300 to 520,
and IBRION=-1 of course.
To solve such convergence problem, I also tried Gaussian Smearing with 1 kpoints or mixing parameters for molecules:
Code: Select all
AMIX = 0.2
BMIX = 0.0001
AMIX_MAG = 0.8
BMIX_MAG = 0.0001
Is there anything wrong in my inputs or what else can I try?
ALGO = 38? Manually set NGX ot NGXF?
Anything suggestions would helpful!!
<span class='smallblacktext'>[ Edited ]</span>
