sanitize molecule names for dfhelper

[loriab]

Description

User API & Changelog headlines

• While not recommended to use a / character in your molecule labels, if you do, at least now it won't segfault if density fitting is involved. Thanks to @bennybp for the bug report.

Dev notes & details

• Error can be triggered with below. Shows up in DFHelper::put_tensor()

import psi4

mymol = psi4.Molecule.from_arrays(geom=[0, 0, 0, 2, 0, 0], elem=["h", "h"], name="h2/mol")

# segfaults if any DF (that is, following line commented). runs if DF suppressed (following line active)
#psi4.set_options({"scf_type": "pk", "df_basis_guess": "false"})

ene = psi4.energy("b3lyp/cc-pvtz", molecule=mymol)
print(ene)

Checklist

• Tests added for any new features
• All or relevant fraction of full tests run

Status

• Ready for review
• Ready for merge

[JonathonMisiewicz]

Can we have a test case, out of paranoia?

[loriab]

Can we have a test case, out of paranoia?

Sure thing, added.