# fcidump_from_file

`psi4.driver.``fcidump_from_file`(fname)

  Function to read in a FCIDUMP file.

  Returns: | a dictionary with FCIDUMP header and integrals

  The key-value pairs are:
    - ‘norb’ : number of basis functions
    - ‘nelec’ : number of electrons
    - ‘ms2’ : spin polarization of the system
    - ‘isym’ : symmetry of state (if present in FCIDUMP)
    - ‘orbsym’ : list of symmetry labels of each orbital
    - ‘uhf’ : whether restricted or unrestricted
    - ‘enuc’ : nuclear repulsion plus frozen core energy
    - ‘epsilon’ : orbital energies
    - ‘hcore’ : core Hamiltonian
    - ‘eri’ : electron-repulsion integrals

  Parameters: | fname – FCIDUMP file name