***,h2o                   !A title
r=1.85,theta=104          !set geometry parameters
geometry={o;              !z-matrix geometry input
          h1,O,r;
          h2,O,r,H1,theta}
basis=vtz                 !use VTZ basis
hf                        !closed-shell scf
ccsd(t)                   !do ccsd(t) calculation
casscf                    !do casscf calculation
mrci                      !do mrci calculation