(1) 4C1 [t t t t G+ g-]
(2) 4C1 [t t t t T g+]
(3) 1C4 [t g+ g-- g- G+ g+]
(4) 1C4 [g-- g++ g-- g++ G- g-]
The MP2/cc-pVDZ equiliblium molecular geometries from ref. 10.