psi4.driver.p4util.fcidump(wfn, fname='INTDUMP', oe_ints=None)[source]

Save integrals to file in FCIDUMP format as defined in Comp. Phys. Commun. 54 75 (1989), https://doi.org/10.1016/0010-4655(89)90033-7 . Additional one-electron integrals, including orbital energies, can also be saved. This latter format can be used with the HANDE QMC code but is not standard.

  • wfn (Wavefunction) – Set of molecule, basis, orbitals from which to generate FCIDUMP file.

  • fname (str) – Name of the integrals file, defaults to INTDUMP.

  • oe_ints (Optional[List]) – List of additional one-electron integrals to save to file. So far only EIGENVALUES is a valid option.


ValidationError – When SCF wavefunction is not RHF.


>>> # [1] Save one- and two-electron integrals to standard FCIDUMP format
>>> E, wfn = energy('scf', return_wfn=True)
>>> fcidump(wfn)
>>> # [2] Save orbital energies, one- and two-electron integrals.
>>> E, wfn = energy('scf', return_wfn=True)
>>> fcidump(wfn, oe_ints=['EIGENVALUES'])