Accurate spectroscopic calculations of 21 electronic states of ClO radical including transition properties

作者：Wang, Xinxin; Shi, Deheng^*; Sun, Jinfeng; Zhu, Zunlue

来源：Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy , 2016, 165: 90-98.

DOI：10.1016/j.saa.2016.04.007

• Potential energy curve
• Spectroscopic property
• Scalar relativistic correction
• Core-valence correlation correction
• Electronic transition

The potential energy curves were calculated for the 21 states (X-2 Pi, A(2)Pi, 3(2)Pi, 4(2)Pi, 5(2)Pi,1(2)Sigma(+), 2(2)Sigma(+), 3(2)Sigma(+), 1(2)Sigma(-), 2(2)Sigma(-), 3(2)Sigma(-),1(2)Delta, 2(2)Delta, 3(2)Delta, 1(2)Phi, 1(4)Sigma(+), a(4)Sigma(-), 2(4)Sigma(-),1(4)Pi, 2(4)Pi and 1(4)Delta), which originated from the two lowest dissociation channels of ClO radical. The calculations were done for internuclear separations approximately from 0.08 to 1.10 nm using the CASSCF method, which was followed by the icMRCI approach with the aug-cc-pV5Z basis set. Of these 21 states, the 1(4)Pi, 2(4)Pi, 3(2)Delta, 4(2)Pi, 5(2)Pi,1(2)Phi, 3(2)Sigma(+), 1(4)Delta and 2(4)Sigma(-) states are repulsive. The 1(2)Delta,1(2)Sigma(-), 1(4)Sigma(+), 2(2)Sigma(-), 1(2)Sigma(+), 2(2)Sigma(+), 2(2)Delta and 3(2)Sigma(-) states are very weakly bound. Only the A(2)Pi state has one barrier. The avoided crossing exists between the A(2)Pi and the 3(2)Pi state. However, the avoided crossing does not generate any double wells. Core-valence correlation correction was accounted for at the level of an aug-ccpCVQZ basis set. Scalar relativistic correction was included by the third-order Douglas-Kroll Hamiltonian approximation at the level of an aug-cc-pVQZ basis set. All the potential energy curves were extrapolated to the complete basis set limit. The spectroscopic parameters were determined. The 1(2)Sigma(-), 2(2)Sigma(-), 3(2)Sigma(-) and 1(4)Sigma(+) states may be very difficult to be detected in an experiment, since each of these A-S states has only one or two vibrational states. The Franck-Condon factors and radiative lifetimes were calculated for several low vibrational levels of the A(2)Pi - X-2 Pi, 3(2)Pi - a(4)Sigma(-), 2(2)Delta - a(4)Sigma(-) and 3(2)Sigma(-) - 1(2)Sigma(-) transitions. The spin-orbit coupling effect on the spectroscopic parameters of the X-2 Pi, A(2)Pi, 3(2)Pi, a(4)Sigma(-) and 2(2)Sigma(+) states were discussed. The spectroscopic properties reported here can be expected to be reliably predicted ones.

• 出版日期2016-8-5
• 单位河南师范大学