Potential curves and spectroscopic properties for the ground state of ClO and for the ground and various excited states of ClO−

Abstract

The potential curves and dissociation energies for the ground states of ClO(2Π) and ClO−(1Σ+) and possible low lying excited states (1Π, Π3, Σ−3, Σ+3, Δ1, etc.) of ClO− have been investigated using sophisticated ab initio quantum mechanical techniques with large basis sets including diffuse functions. The equilibrium bond distance and vibrational frequency for the ground state (1Σ+) of ClO− are predicted to be 1.688 Å and 660 cm−1 at the coupled-cluster single double (triple) [CCSD(T)]/aug-cc-pVQZ level of theory. The lowest excited singlet state of ClO− is predicted to be the open-shell Π1 state, which is 2.43 eV higher in energy than the ground state, while the lowest triplet state (3Π) of ClO− has a potential with well depth of 0.32 eV. The adiabatic electron detachment energy from ClO− is predicted to be 2.29 eV including zero-point vibrational energy (ZPVE) at the CCSD(T)/aug-cc-pVQZ level of theory. The spin allowed vertical electronic transition (1Σ+–1Π) of ClO− is predicted to be 3.13 eV including ZPVE. The dissociation energies (D0) of ClO− to Cl−(1S)+O(3P), Cl−(1S)+O(1D), and Cl(2P)+O−(2P) are predicted to be 1.40, 3.46, and 3.61 eV, respectively, including ZPVE.