problem for a large molecular system
Posted: Sat Jun 16, 2007 1:19 am
Hi!
I am trying to make a VASP calculation for a molecular system which consists of 199 atoms. In more detail, there are 108, 4, 8, 4, 78, and 1 atoms for C, O, N, S, H, and Ru.
The lattice parameter is very big. I use orthorhombic cell with Lx, Ly, Lz = (25, 29, 22)A. I canot reduce the size any more. In addition, I cannot use other kind of supercell.
When I tried to optimize the geometry, it did not run even one step. Namely, an electronic SCF calculation for a given geometry cannot be successfully finished. The error message I get is:
"1525-108 Error encountered while attempting to allocate a data object. The program will stop."
In the POSCAR file, I use the parameters
PREC=Nornal
ALGO=Normal
ENMAX = 400
LREAL = Auto
Since there are many hydrogen atoms, the cut-off energy cannot be no smaller than 400eV.
Could you help me find out the way to solve this probelm?
Hong Seok Kang
hsk@jj.ac.kr
I am trying to make a VASP calculation for a molecular system which consists of 199 atoms. In more detail, there are 108, 4, 8, 4, 78, and 1 atoms for C, O, N, S, H, and Ru.
The lattice parameter is very big. I use orthorhombic cell with Lx, Ly, Lz = (25, 29, 22)A. I canot reduce the size any more. In addition, I cannot use other kind of supercell.
When I tried to optimize the geometry, it did not run even one step. Namely, an electronic SCF calculation for a given geometry cannot be successfully finished. The error message I get is:
"1525-108 Error encountered while attempting to allocate a data object. The program will stop."
In the POSCAR file, I use the parameters
PREC=Nornal
ALGO=Normal
ENMAX = 400
LREAL = Auto
Since there are many hydrogen atoms, the cut-off energy cannot be no smaller than 400eV.
Could you help me find out the way to solve this probelm?
Hong Seok Kang
hsk@jj.ac.kr