Cell optimization and atomic relaxation
Posted: Thu Apr 25, 2013 3:29 pm
Hi,
I would like to perform a cell optimization and a structural relaxation of the atoms. But I don't know which method is more efficient/faster:
- cell optimization AND atomic relaxation at the same time (IBRION=2 and ISIF=3) or,
- cell optimization first, then a structural relaxation (or conversely).
For the second option, how could I do this? In fact, when I optimize the cell while keeping the atoms fixed (IBRION=-1 and ISIF=6), the forces acting on the atoms do not change (and is thus never lower than EDIFFG) and the calculation does not stop until NSW is reached.
Thanks for your help
L.
I would like to perform a cell optimization and a structural relaxation of the atoms. But I don't know which method is more efficient/faster:
- cell optimization AND atomic relaxation at the same time (IBRION=2 and ISIF=3) or,
- cell optimization first, then a structural relaxation (or conversely).
For the second option, how could I do this? In fact, when I optimize the cell while keeping the atoms fixed (IBRION=-1 and ISIF=6), the forces acting on the atoms do not change (and is thus never lower than EDIFFG) and the calculation does not stop until NSW is reached.
Thanks for your help
L.