source: ThirdParty/mpqc_open/src/bin/mpqc/sample/hbondopt.in

% emacs should use -*- KeyVal -*- mode
% molecule specification
molecule<Molecule>: (
  symmetry = C1
  { atoms geometry } = {
      H    [ 0.088    2.006    1.438 ]
      O    [ 0.123    3.193    0.000 ]
      H    [ 0.088    2.006   -1.438 ]
      O    [ 4.502    5.955   -0.000 ]
      H    [ 2.917    4.963   -0.000 ]
      H    [ 3.812    7.691   -0.000 ]
  }
)
% basis set specification
basis<GaussianBasisSet>: (
  name = "STO-3G"
  molecule = $:molecule
)
mpqc: (
  checkpoint = no
  savestate = no
  % method for computing the molecule's energy
  mole<CLHF>: (
    molecule = $:molecule
    basis = $:basis
    coor = $..:coor
    memory = 16000000
  )
  % molecular coordinates for optimization
  coor<SymmMolecularCoor>: (
    molecule = $:molecule
    % give an internal coordinate generator that knows about the
    % hydrogen bond between atoms 2 and 5
    generator<IntCoorGen>: (
      molecule = $:molecule
      extra_bonds = [ 2 5 ]
    )
  )
  % optimizer object for the molecular geometry
  opt<QNewtonOpt>: (
    function = $..:mole
    update<BFGSUpdate>: ()
    convergence<MolEnergyConvergence>: (
      cartesian = yes
      energy = $..:..:mole
    )
  )
)