psi: (
  label = "DZP RHF optimization of C2H6"
  wfn = scf
  reference = rhf
  jobtype = opt
  dertype = first
  docc = (4 1 1 3)
  basis = "DZP"
% uses z-matrix to specify which coordinates are optimized
  zmat_simples = true
  zmat = (
    H
    C 1 CH$
    C 2 CC$ 1 HCC$
    H 3 CH$ 2 HCC$ 1 60.0
    H 3 CH$ 2 HCC$ 1 -60.0
    H 3 CH$ 2 HCC$ 1 180.0
    H 2 CH$ 3 HCC$ 6 60.0
    H 2 CH$ 3 HCC$ 6 -60.0
  )
  zvars = (
    CH 0.9
    CC 1.5
    HCC 109.45
  )
)
