Save orbitals and restart SCF


Hello All,

A very basic question, that I didn’t manage to find a working solution for:

How do I save the orbitals after a calculation, and use them for an SCF restart? Searching the forum, I find mentions of a “180” file, the “-m” option to psi4 etc., but I have not figured it out yet…

I would need this specifically for two cases:

  1. Restart from the last orbitals, if maxiter was reached before convergence. Then I could switch to, say, SOSCF after a hundred standard iterations if convergence stagnates.

  2. Use converged orbitals as input for a SAPT calculation.

A step by step example would be most appreciated! I am using PSI4 version 1.3.