#! Mk-MRCCSD(T) single point. $^1A@@1$ O$@@3$ state described using
#! the Ms = 0 component of the singlet.  Uses TCSCF orbitals.

memory 250 mb


molecule ch2 {
  0 1
    O        -2.044380893268     0.426793459237     0.000000000000
    O        -0.001248077996    -0.852806209845     0.000000000000
    O         2.045628971264     0.426012750608     0.000000000000

  units au
}

set {
  basis DZ
  e_convergence 10
  d_convergence  8
  r_convergence  8
}

set mcscf {
  reference       twocon
  # The socc and docc needn't be specified; in this case the code will converge correctly without
  docc            [10,1]      # Doubly occupied MOs
  socc            [ 0,2]      # Singly occupied MOs
  maxiter         300
  canonicalize_active_favg true
}

set psimrcc {
  corr_wfn        ccsd_t       # Do Mk-MRCCSD(T) 
  frozen_docc     [3,0]        # Frozen MOs
  restricted_docc [7,1]        # Doubly occupied MOs
  active          [0,2]        # Active MOs
  frozen_uocc     [0,0]        # Frozen virtual MOs
  corr_multp      1            # Select the Ms = 0 component
  wfn_sym         Ap           # Select the A1 state
}

energy('psimrcc')
