Ab initio investigation of the ground and excited states of TcO+ and RhO+

High-level quantum calculations are utilized to analyze nineteen and thirteen lowest energy electronic states of TcO+ and RhO+ . Their potential energy curves, equilibrium bond lengths, electronic excitation energies, harmonic vibrational frequencies, and anharmonicities are reported using quadruple-zeta and quintuple-zeta quality correlation consistent basis sets. The core electron correlation effects and equilibrium chemical bonding patterns of several low-energy electronic states are also considered. The ground state of TcO+ (1(1)Sigma(+)) (1 sigma(2) 1 pi(4) 1 delta(4)) is triple bonded in nature, results adiabatically from the high energy Tc+ (P-3) + O(P-3) fragments, and relates to the first excited state of TcO ((2)Sigma(+)) (1 sigma(2) 2 sigma(1) 1 pi(4) 1 delta(4)). The chemical bonding of TcO+ (1(1)Sigma(+)) is identical to its isoelectronic RuO2+ (X-1 Sigma(+) ) ground state. The ground state of RhO+ ((3)Sigma(-)) features a 1 sigma(2)1 pi(4)1 delta(4)2 pi(2) electronic configuration. Moving from TcO+ to RhO+ the binding energy decreases by similar to 15-20 kcal/mol, the metal-oxygen bond shortens by 0.07 A, and the harmonic stretching frequency decreases by similar to 170 cm(-1) . Bonding patterns and spectroscopic constants are compared for the neighboring species of RhO+ and TcO+. (C) 2022 Elsevier Ltd. All rights reserved.

Automated summary

High-level quantum calculations were used to analyze the lowest energy electronic states of TcO+ and RhO+. The potential energy curves, bond lengths, excitation energies, vibrational frequencies, and bonding patterns were reported. The results were compared with neighboring species.