Computation fails for a dense K-point mesh
Posted: Mon Jul 15, 2013 7:00 am
I performed calculations on the simple hcp Co. I was doing a supercell (frozen phonon like) calculation for a 2x2x2 cell, therefore 16 atoms are included.
I need a very precise result. The magnetic moment is need. Since the transition metal is very sensitive to the K-point mesh, I was doing a kpoint convergence.
The program runs fine for a kpoint mesh of 16x16x8, 16x16x10, and 20x20x10. However, the results are not converged well. When I continued to increase the kpoint mesh to 20x20x12 (NKPTS=1414), the calculation fails. The error message shows:
forrtl: severe (174): SIGSEGV, segmentation fault occurred
Even I parallelized the calculation on 256 cores, it is still not able to finish correctly.
What should I do?
My calculation is performed on the Carver cluster at NERSC machines.
The following is my INCAR file.
--------INCAR----------
SYSTEM = Co
ISMEAR = 1
SIGMA = 0.1
IBRION = -1
ENCUT = 350
PREC = ACCURATE
NSW = 0
LREAL = .FALSE.
#LORBIT = 11
ISPIN = 2
#GGA = PS
NGX = 32
NGY = 32
NGZ = 52
EDIFF=1E-6
#ALGO = NOTHING
MAGMOM = 16*2
LWAVE = .FALSE.
LCHARG = .FALSE.
NPAR = 8
#KPAR = 2
------end of INCAR-----------
I need a very precise result. The magnetic moment is need. Since the transition metal is very sensitive to the K-point mesh, I was doing a kpoint convergence.
The program runs fine for a kpoint mesh of 16x16x8, 16x16x10, and 20x20x10. However, the results are not converged well. When I continued to increase the kpoint mesh to 20x20x12 (NKPTS=1414), the calculation fails. The error message shows:
forrtl: severe (174): SIGSEGV, segmentation fault occurred
Even I parallelized the calculation on 256 cores, it is still not able to finish correctly.
What should I do?
My calculation is performed on the Carver cluster at NERSC machines.
The following is my INCAR file.
--------INCAR----------
SYSTEM = Co
ISMEAR = 1
SIGMA = 0.1
IBRION = -1
ENCUT = 350
PREC = ACCURATE
NSW = 0
LREAL = .FALSE.
#LORBIT = 11
ISPIN = 2
#GGA = PS
NGX = 32
NGY = 32
NGZ = 52
EDIFF=1E-6
#ALGO = NOTHING
MAGMOM = 16*2
LWAVE = .FALSE.
LCHARG = .FALSE.
NPAR = 8
#KPAR = 2
------end of INCAR-----------