Fachbereich C, Theoretische Chemie, Bergische Universität Wuppertal, Gaußstr. 20, D-42097 Wuppertal, Germany.
J Chem Phys. 2012 Jun 14;136(22):224307. doi: 10.1063/1.4727851.
Multireference configuration interaction calculations have been carried out for low-lying electronic states of AsH(3). Bending potentials for the nine lowest states of AsH(3) are obtained in C(3v) symmetry for As-H distances fixed at the ground state equilibrium value of 2.850 a(0), as well as for the minimum energy path constrained to R(1) = R(2) = R(3). The calculated equilibrium geometry and bond energy for the X (1)A(1) ground state agree very well with the previous experimental and theoretical data. It is shown that the lowest excited singlet state belongs to the (1)A(1) symmetry (in C(3v)), in contradiction to the previous calculations. This state is characterized by a planar equilibrium geometry. Asymmetric stretch potential energy surface (PES) cuts along the H(2)As-H recoil coordinate (at R(1) = R(2) = 2.850 a(0), θ = 123.9° and 90°) for numerous excited states and two-dimensional PESs for the X and à states up to the dissociation limits are obtained for the first time. The à (1)A(1), B(1)E-X (1)A(1) transition moments are calculated as well and used together with the PES data for the analysis of possible photodecay channels of arsine in its first absorption band.
多参考组态相互作用计算已应用于低能态的 AsH(3)。在 C(3v)对称下，As-H 距离固定在基态平衡值 2.850 a(0)，以及在最低能量路径上约束为 R(1) = R(2) = R(3)，得到了 AsH(3)的九个最低能态的弯曲势。计算得到的 X (1)A(1)基态平衡几何形状和键能与之前的实验和理论数据非常吻合。结果表明，最低激发单重态属于 (1)A(1)对称（在 C(3v)中），与之前的计算结果相反。这个态的平衡几何形状是平面的。首次获得了沿 H(2)As-H 反冲坐标（在 R(1) = R(2) = 2.850 a(0)，θ = 123.9°和 90°）的许多激发态和二维 PES 的不对称拉伸势能面（PES）的截面，以及 X 和 Ã 态直至离解极限的 PES。Ã (1)A(1)、B(1)E-X (1)A(1)跃迁矩也被计算出来，并与 PES 数据一起用于分析砷烷在其第一吸收带中可能的光解通道。
