Fachbereich C, Theoretische Chemie, Bergische Universität Wuppertal, Wuppertal, Germany.
J Chem Phys. 2011 Dec 28;135(24):244303. doi: 10.1063/1.3671374.
Multireference configuration interaction calculations have been carried out for low-lying electronic states of AsH(2). Bending potentials for the ten lowest states of AsH(2) are obtained in C(2v) symmetry for As-H distances fixed at the the ground state equilibrium value of 2.845 a(0), as well as for the minimum energy path constrained to R(1) = R(2). The calculated equilibrium geometries for the X̃(2)B(1) ground state and the Ã(2)A(1) excited state agree very well with the previous experimental and theoretical results, whereas the data for the higher-lying states are obtained for the first time. Asymmetric potential energy surface (PES) cuts (at R(1) = 2.845 a(0), θ = 90.7°) and two-dimensional (2D) PESs for the lowest three states are also new. The calculated ab initio data are used for analysis of possible AsH(2) photodissociation channels and predissociation effects. It is shown that the Ã(2)A(1)-X̃(2)B(1) transition dipole moment decreases with increasing bending angle, which influences the intensity distribution in the Ã(0,0,0)→X̃ emission spectrum (v(2)'' bending series), shifting its maximum to smaller v(2)'' quantum numbers.
多参考组态相互作用计算已应用于低能态的 AsH(2)。在 As-H 距离固定在基态平衡值 2.845 a(0)以及最小能量路径约束在 R(1)=R(2)的 C(2v)对称条件下，得到了 AsH(2)的十个最低态的弯曲势能。计算得到的 X̃(2)B(1)基态和 Ã(2)A(1)激发态的平衡几何结构与之前的实验和理论结果非常吻合，而对于较高能态的数据则是首次获得。非对称位能面 (PES) 切割（在 R(1)=2.845 a(0)，θ=90.7°）和三个最低态的二维 (2D) PES 也是新的。计算的从头算数据用于分析可能的 AsH(2)光解通道和预解离效应。结果表明，Ã(2)A(1)-X̃(2)B(1)跃迁偶极矩随弯曲角度的增加而减小，这影响了 Ã(0,0,0)→X̃发射光谱（v(2)''弯曲系列）中的强度分布，将其最大值移向较小的 v(2)''量子数。
