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You can choose an avatar and change the default style by going to "Profile" → "Personality" or "Display".#1 2018-07-20 08:51:35
- ethanthomas
- Member
- Registered: 2018-07-17
- Posts: 4
Number of processors needed to compute numerical gradients efficiently
I just wanted to know how many processors can Molcas efficiently use when computing numerical gradients for a CASPT2 optimizations. Someone told me 4 but, why not 8?
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#2 2018-07-20 13:33:31
- valera
- Administrator
- Registered: 2015-11-03
- Posts: 129
Re: Number of processors needed to compute numerical gradients efficiently
There is a fantastic rule, called Garbage Input -Garbage Output. 
The correct answer depends on many factors about your run, which you didn't specify. In a simple way, the number of displacements in NG is the ideal number for MOLCAS_NPROCS. But you also should consider the fact that if these processes are not individual CPUs, but cores - you might hit a limit in I/O.
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