problem with loops over basis sets in psi4 using python
Here is an input file that will reproduce this error:



molecule {
    b      0.0000        0.0000        0.0000
    h      0.0000        0.0000        1.0000
}

basis_sets = ["6-31G", "6-31G*", "6-31G**"]
for basis_set in basis_sets:
    set basis = $basis_set
    energy('scf')


The problem is that Psi4 sees there are files remaining in scratch that it can use, starting with the spin orbital-basis overlap integrals, but because the basis set has changed, the file is the wrong size. You'll need to clean these up after the energy call by adding clean() within the loop.