Potential energy functions of the X̃ 2B1, Ã 2B2, B̃ 2A1, and C̃ 2A2 states of Cl2O+ and the X̃ 1A1 state of Cl2O: Franck–Condon simulations of photoelectron bands of Cl2O which include anharmonicity

Abstract

Restricted-spin coupled-cluster single and double plus perturbative triple excitations ͓RCCSD ͑T͔͒ and/or complete-active-space self-consistent-field multireference internally-contracted configuration interaction ͑CASSCF/MRCI͒ potential energy functions of the

Simulating the HeI photoelectron spectrum of Cl2O with new full-dimensional adiabatic potential energy surfaces of Cl2O(X̃1A1), Cl2O+(X̃2B1), and Cl2O+(C̃2A2) and a three-state diabatic potential energy matrix of Cl2O+(Ã2B2, B̃2A1, and 22A1): a quantum mechanical study

“…Subsequently, the HeI photoelectron spectrum of Cl 2 O was reinvestigated by Chau et al through computing Franck-Condon factors based on the ab initio data, in which the anharmonicity was introduced in the calculations. 18 It was found that the first, second and fourth bands were consistent with the experimental envelope. In particular, the first and second bands were in better agreement with experiment than the results from earlier harmonic IFCA calculations.…”

“…Table 2 lists the equilibrium geometrical parameters and harmonic frequencies of the ground state for neutral Cl 2 O(X ˜1A 1 ), and vertical ionization energies (VIEs) of the four lowest cationic states, together with previous theoretical results, [17][18][19] and available experimental data 4,5,23,24 for comparison. It can be seen that the geometries obtained at the RCCSD(T)-F12 and MRCI-F12+Q levels with the cc-pCVXZ-F12(X = D, T, Q) basis set are consistent with each other and in good accord with the experimental results.…”

“…using the CIS/ 6-311+G(2d) method. 18 It can be seen from Table 1 that the 2 2 A 1 state of Cl 2 O + has the typical multiconfigurational character. Considering the multiconfigurational character of this electronic state and large basis sets used in our MRCI-F12+Q calculations, our calculated structure of this state should be more precise.…”

“…It is well known that halogen oxides such as Cl 2 O can be easily photolyzed or dissociated into radicals that have been found to take part in the reactions of the destruction of ozone. [1][2][3] Spectroscopy, 4,5 photoionization, 6 photoelectron spectroscopy, [7][8][9][10][11][12][13] and photophysical and photochemical [14][15][16][17][18][19] studies of Cl 2 O have been extensively carried out for gaining a deep understanding of the behavior of relevant halogen oxide species in the stratosphere. Moreover, the photoabsorption spectra in the infrared, visible, ultraviolet and vacuum ultraviolet regions of Cl 2 O have received considerable attention as well.…”

Photodissociation Dynamics of Cl2O: Interpretation of Electronic Transitions

“…Photochemistry and photophysics of Cl 2 O have recently received considerable attention for several reasons. − The photochemistry of chlorine oxides is of general interest due to their role in atmospheric chemistry, although Cl 2 O does not directly take part in the ozone depletion process in the stratosphere. Discrepancies in the assignment of its excited electronic states ,− exist, as well as disagreement between experimental and theoretical data with respect to its dissociation dynamics, ,, both of which have not completely been resolved until now.…”