I’ve seen that a few people asked related things, but I could find a direct answer. Sorry if I missed the relevant thread.
I am doing a single point calculation that reaches a timeout on the HPC, because the molecule is on the larger side, and I wanted to restart/continue from the fchk file. My input file looks as follows:
set maxiter 500
set freeze_core True
set PROPERTIES_ORIGIN [“COM”]
set cubeprop_tasks [‘esp’]
set basis aug-cc-pVTZ
E, wfn = properties(‘mp2’,properties=[‘dipole’],return_wfn=True)
A fchk was written, so I would like to read and continue form there.
Thx a lot in advance!
Thanks a lot for the quick reply and the suggestions!
I’ll try it according to 2.
Regarding 3, there’s no specific reason, I guess - I’ll try it as you suggested.
Since you are performing an MP2 job, there are two different meanings for ‘restart from fchk’:
(1) read converged HF orbitals from fchk file and start the from MP2 calculation;
(2) read (if possible) the MP2 amplitudes from any Psi4-native file and compute the MP2 correlation energy directly.
where case (2) may be difficult since canonical MP2 amplitudes are computed using orbital energies and two-electrons integrals and thus amplitudes are seldom to be saved into file (as far as I know).
Case (1) is usually simple. For example, one can use the utility
fch2psi to generate PSI4 input files (an
inp file and an orbital file) from a given .fch(k) file. The utility
fch2psi is open-sourced