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6.5 Restarts and Checkpoints
FILE save=molecule
TEXT= B3LYP/6-31G* optimization from RHF/3-21G archive
GEOM=read
! -------------- get geometry from old <coord>
BASIS=6-31G*
GUESS=READ
! -------------- use old MOs as initial guess
OPTIM
! -------------- will automatically pick up any
GUESS=READ
!
pre-existing .hess file
SCF dftp=b3lyp
FORCE
JUMP
The following files need to be available in the directory in which the new job is being ran: .control,
.coord, .basis, .mos, .hess.
Geometry optimizations can easily be restarted from the .optchk file following job crashes. This is not
necessarily the case if the job aborts with an error message.
The OPTIMIZE module is set up to automatically read data from the .optchk file if one exists. To
restart a job that crashes somewhere in the main optimization loop use
TEXT= Restart following
GEOM=read
BASIS=6-31G*
OPTIM
SCF dftp=b3lyp
FORCE
JUMP
job crash
! --------------
must use current geometry
! -------------!
will automatically pick up data
from .optchk file
Tip:
The original input geometry (if one was given in the input file) must be removed
and either replaced with the current geometry or (better) by a direct read from the latest
.coord file (as shown above).
Note:
The geometry optimization restart is different from earlier versions of PQS
(3.1 and earlier) in that there is no longer any need to add SCF and FORCE cards before
the OPTIM card as was previously the case.
6.5.2
Numerical Hessian
Frequency runs that crash in the numerical Hessian loop can be restarted from the .hesschk file. The
restart procedure is very similar to the restart of a geometry optimization from the .optchk file. To
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PQS Manual