super cell and convergence
Posted: Tue Mar 27, 2012 6:25 pm
Hi:
I have carried out a super cell calculation of MnSi system. The dimensions of the cell are 5.52, 5.52, and 96.2. The issue that I am facing is that after convergence when I look at the density of states it not correct. I had similar issues whenever I use cell with z axis much longer than x and y. Sometime the calculation never converged or when it converged the results are not correct.
Has anyone encountered similar issue? I am pretty new to these calculations. My questions are: Is it possible to do calculation on cells with short x and y axis (~ 6 Angstroms) and long (around 100 Angstroms) z axis? Or is there any limitation in using VASP for these calculations. My INCAR file is given below.
PREC = normal
ENCUT=300
ISTART=1
ISYM=0
ISMEAR=-5
NEDOS=1000
LORBIT = 11
LMAXMIX = 4
LREAL=Auto
If it is possible to do a VASP calculation on this elongated cell are there any options that need to be added to the INCAR file. I would really appreciate it, if somebody could comment on this particular issue.
Thanks
Deena
I have carried out a super cell calculation of MnSi system. The dimensions of the cell are 5.52, 5.52, and 96.2. The issue that I am facing is that after convergence when I look at the density of states it not correct. I had similar issues whenever I use cell with z axis much longer than x and y. Sometime the calculation never converged or when it converged the results are not correct.
Has anyone encountered similar issue? I am pretty new to these calculations. My questions are: Is it possible to do calculation on cells with short x and y axis (~ 6 Angstroms) and long (around 100 Angstroms) z axis? Or is there any limitation in using VASP for these calculations. My INCAR file is given below.
PREC = normal
ENCUT=300
ISTART=1
ISYM=0
ISMEAR=-5
NEDOS=1000
LORBIT = 11
LMAXMIX = 4
LREAL=Auto
If it is possible to do a VASP calculation on this elongated cell are there any options that need to be added to the INCAR file. I would really appreciate it, if somebody could comment on this particular issue.
Thanks
Deena