Q: I have deleted the files energy, gradient and forceapprox in order to start a new geometry optimization on the same system using the old control file. DSCF and GRAD run properly, but RELAX crashes with the error
force constant matrix will be read from $forceapprox
$forceapprox : could not find file !
relax step ended abnormally
STOP HREAD : error reading $forceapprox !
Why?
A: Because of the entry $forceinit off in the old control file, RELAX expects to find the approximate force constants to help it update the geometry. Change this to $forceinit on (simply enter finit at the command line to change it), rerun RELAX and then restart the geometry optimization from a DSCF step.
