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Re^3: How to speed up the HESSIAN calculations

Luca Maidich
luca.maidich@gmail.com


Dear Siddheshwar,
as Thomas said already there aren't many ways of speeding up hessian evaluation in your case. Just to add other options you can:
- Change to NVIB=1 in $FORCE to halve the number of single point energy calculations (from 6N+1 to 3N+1) with only a slight difference in the frequencies, but I suggest you to check yourself if the difference is not dramatic by running both calculations, i.e. with NVIB=1 and NVIB=2.
- Run the job on more CPU cores even if this is not something connected to your input file.
Other options, to the best of my knowledge, require lowering the accuracy as Thom pointed out...

Kind Regards
Luca


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