Gaussian - How Restart What

Written by Super User. Posted in Uncategorised

Restarting failed Gaussian runs can be a pain. First of all: be sure that you use the same type of machine: The checkpoint files are NOT transferable. In case a change is neccesary: Try formchk and reverse operation unfchk. My personal experience: it does not work. Most probably because i am too unpatient, forget something and at some point mess up my chk files. MAKE BACKUPS

Here are at least two restarts that actually work well for me:

Unconverged SCF:

just add  SCF=(restart) to the input block

Add some states to a TDDFT calculation:

#P wB97XD Geom=AllCheck ChkBas Guess=(Read,Only) td(read,add=15)