***,OH
include procedures
geometry={O;H,O,1.83}
set,symmetry=2,spin=1   ! X 2 Pi state
runccsdt
epi=energy
set,symmetry=1,spin=1   ! A 2 Sigma+ state
runccsdt
esig=energy
de=(esig-epi)*toev     !Excitation energy in eV