Nearly-degenerate electronic states for Ga3P2 and Ga2P3

Nearly-degenerate 2A1 and 2B1(C2y) electronic states are found with distorted trigonal bipyramid and edge-capped tetrahedral geometries together with a E′(D3h) state for Ga3P2, while a distorted structure with 2B1 symmetry and a 2A″2 undistorted D3h structure are found to be nearly-degenerate for Ga2P3. We employ the complete active space multi-configuration self-consistent field followed by multi-reference singles + doubles configuration interaction (MRSDCI) computations that included up to 2.5 million configurations.