Methylene: Adiabatic excitation energies FCI/TZ2P optimized geometries used. The TZ2P basis set and high-spin UHF reference used for the single point calculations Equilibrium geometry used: (FCI/TZ2P) 3B1 (reference) state geometry: -------------------------- C H 1 rCH H 1 rCH 2 HCH rCH = 1.0775 HCH = 133.29 Nuclear Repulsion Energy = 6.1608618178 hartrees SF calculation using high-spin triplet reference EHF = -38.937955569 EMP2 = -39.060862657 CCSDT Total Energy = -39.08432012 --------------------------- a 1A1 state geometry: C H 1 rCH H 1 rCH 2 HCH rCH = 1.1089 HCH = 101.89 Nuclear Repulsion Energy = 6.0337753316 hartrees EHF = -38.919791792 EMP2 = -39.043043599 CCSDT Total Energy = -39.06679199 ------- b 1B1 state geometry: C H 1 rCH H 1 rCH 2 HCH rCH = 1.0748 HCH = 141.56 Nuclear Repulsion Energy = 6.1688997427 hartrees EHF = -38.936751546 EMP2 = -39.059890913 CCSDT Total Energy = -39.08351290 ------- c 1A1 state geometry: C H 1 rCH H 1 rCH 2 HCH rCH = 1.0678 HCH = 170.08 Nuclear Repulsion Energy = 6.1956449370 hartrees EHF = -38.927357576 EMP2 = -39.051124228 CCSDT Total Energy = -39.07551613 --------------------------- --------------------------- Nitrenium: The CISD/TZ2P(f,d) optimized geometries used The TZ2Pf basis set and high-spin UHF reference used for the single point calculations ------- 3B1 (reference) state geometry: N H 1 rNH H 1 rNH 2 HNH rNH = 1.0295 HNH = 150.88 Nuclear Repulsion Energy = 7.4617278181 hartrees EHF = -55.236748697 EMP2 = -55.383288172 CCSDT Total Energy = -55.40689198 ------- a 1A1 state geometry: N H 1 rNH H 1 rNH 2 HNH rNH = 1.0459 HNH = 107.96 Nuclear Repulsion Energy = 7.3961310239 hartrees EHF = -55.211387188 EMP2 = -55.359560032 CCSDT Total Energy = -55.38289458 ------- b 1B1 state geometry: N H 1 rNH H 1 rNH 2 HNH rNH = 1.0293 HNH = 161.47 Nuclear Repulsion Energy = 7.4580461860 hartrees EHF = -55.236144178 EMP2 = -55.382667311 CCSDT Total Energy = -55.40652476 ------- c 1A1 state geometry: N H 1 rNH H 1 rNH 2 HNH rNH = 1.0315 HNH = 180.00 Nuclear Repulsion Energy = 7.4387489642 hartrees EHF = -55.235010510 EMP2 = -55.381564553 CCSDT Total Energy = -55.40568881 --------------------------- ---------------------------- CH molecule for (SF reference) basis= cc-pVTZ $molecule 0 4 C H 1 1.1198 $end Nuclear Repulsion Energy = 2.83538423 hartrees EHF = -38.2877620999 EMP2 = -38.36649896 CCSDT Total Energy = -38.38523921 -------------------------- CH molecule for (EE reference) basis= cc-pVTZ $molecule 0 2 C H 1 1.1198 $end Nuclear Repulsion Energy = 2.83538423 hartrees EHF = -38.2813521983 EMP2 = -38.38253424 CCSDT Total Energy = -38.41102192 ------------------------------------ for HF 6-31G basis set used and the bond lengths are provided in the table4