The 12A″, 12A′, and 22A′ electronic states of the H2S+ ion studied using multiconfiguration second-order perturbation theory

摘要: Abstract Doublet electronic states of the H2S+ ion, within Cs as well C2v symmetries, were studied using CASSCF and CASPT2 methods in conjunction with an ANO basis. For three lowest-lying (12B1 12A1 12B2) states, CAS (CASSCF CASPT2) calculation results (geometries, frequencies, adiabatic excitation energies (T0)) are similar to those previous MRD-CI MRCI calculations. We consider that assignment B state 12B2 be inappropriate since calculated T0 values for about 1 eV smaller than experimental value state. The potential energy surfaces (PESs) (12A″, 12A′, 22A′) explored by locating characterizing stationary points calculating minimum curves E(θ) (θ = ∠HSH). In 12A″ PES there is a M0. 12A′ PES, global M1, local M2, first-order saddle point TS connecting M1 M2. M0, M2 identified 12B1, 12A1, minima, respectively, while has geometry. geometries frequencies M0 (12A″) (12A′) reasonable agreement data X A respectively. relative 2.38 eV (to M0) good 2.31 eV assign (M1). not involved any process ion. 22A′ M3 was located at geometry level. 4.19 eV quite close 4.31 eV state, we then (M3).