摘要:
采用考虑Davidson修正的内收缩多参考组态相互作用(icMRCI+Q)方法结合相关一致基组aug-cc-pV5Z和aug-cc-pV6Z计算了CF+离子第一离解极限C+(2Pu)+F(2Pu)对应的12个Λ-S态(X1Σ+, a3Π,13Σ+,13?,11?,11Σ?,13Σ?,21Σ+,11Π,23Π,21Π和23Σ+)所产生的23个?态的势能曲线。计算中考虑了旋轨耦合效应、核价相关和标量相对论修正以及将参考能和相关能分别外推至完全基组极限。基于得到的势能曲线,获得了束缚和准束缚的9个Λ-S态和16个?态的光谱常数,并且X1Σ+, a3Π势阱一Λ-S态的光谱常数与已有的实验结果非常符合。此外,计算了CF自由基X2Π态到CF+离子束缚和准束缚的9个Λ-S态的垂直电离势和绝热电离势,并且CF+(X1Σ+)←CF(X2Π)和CF+(a3Π势阱一)←CF(X2Π)的垂直电离势和绝热电离势与相应的实验结果也非常符合。由a3Π,11Π态和其他激发Λ-S态势能曲线的交叉现象,借助于计算的旋轨耦合矩阵元,分析了a3Π势阱一,11Π势阱一和21Σ+态的预解离机理。计算的23个?态离解极限处的相对能量与实验结果十分吻合。最后计算了(2)0+势阱一(υ′=0—5),(1)1势阱一(υ′=0—5)和(2)1势阱一(υ′=0)到X0+态跃迁的Franck-Condon因子和辐射寿命。
Abstract:
The potential energy curves of twenty-three?states generated from the twelveΛ-S states (X1Σ+, a3Π, 13Σ+, 13?, 11?, 11Σ?, 13Σ?, 21Σ+, 11Π, 23Π, 21Π and 23Σ+) correlating with the first dissociation channel C+ (2Pu)+ F(2Pu) of the CF+ cation are obtained by using the internally contracted multireference configuration interaction approach with the Davidson modification (icMRCI+Q) on the basis of the correlation-consistent aug-cc-pV5Z and aug-cc-pV6Z basis sets for the first time. The spin-orbit coupling, core-valence correlation and relativistic corrections are taken into account, and all the potential energy curves are extrapolated to the complete basis set limit by separately extrapolating the Hartree-Fock and correlation energies scheme. Based on the calculated potential energy curves, the spectroscopic parameters of the bound and quasibound nine Λ-S and sixteen ? states of the CF+ cation are obtained. And the spectroscopic parameters of X1Σ+and a3Π1st well Λ-S states which are in very good agreement with experimental results are achieved. Furthermore, the vertical and adiabatic ionization potentials of ionization from the X2Πstate of CF radical to the bound and quasibound nineΛ-S states of the CF+ cation are calculated, and the vertical and adiabatic ionization potentials of the CF+(X1Σ+) ←CF(X2Π) and CF+(a3Π1st well) ←CF(X2Π) ionizations are also in good agreement with the corresponding experimental values. Various curve crossings of Λ-S states are revealed, and with the help of our computed spin-orbit coupling matrix elements, the predissociation mechanisms of the a3Π1st well, 11Π1st well and 21Σ+ states are analyzed for the first time. The spin-orbit-induced predissociations for the a3Π1st well, 11Π1st well and 21Σ+Λ-S states could happen, and the predissociations of the a3Π1st well, 11Π1st well and 21Σ+Λ-S states start around the vibrational levels υ′ = 15, υ′ = 1 and υ′ = 1, respectively. Relative energies of the twenty-three ? states in the dissociation limits are given, and our calculations match the experimental results very well. Finally, the Franck-Condon factors and radiative lifetimes of transitions from (2) 0+ 1st well (υ′=0–5), (1) 11st well (υ′=0–5) and (2) 11st well (υ′=0) to X0+?states are predicted for the future laboratory research.
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