CrHn(n=0,+1,+2)分子及离子的势能函数

用原子分子反应静力学原理推导出CrHⁿ(n=0，+1，+2)的电子状态及其离解极限. 对H原子采用6-311++G^**基组，对Cr原子采用SVP(split valence polarization)全电子基组，用B3PW91方法计算了它们的平衡几何、电子状态，在此基础上分别计算CrH，CrH⁺的Murrell-Sorbie解析势能函数和CrH²⁺的解析势能函数及其对应的力常数、光谱参数，理论计算值与实验值和文献计算值符合较好. 从离解极限和通道解释了不同的势能函数形状. 计算表明：CrH⁺的势能曲线均具有对应于稳定平衡结构的极小点，说明CrH⁺可稳定存在. 而CrH²⁺离子的势能曲线对应于不稳定的排斥态，说明CrH²⁺是不稳定的. 关键词： n(n=0')" href="#">CrHⁿ(n=0 +2) 势能函数 光谱参数 稳定性

Potentional energy function of CrHn(n=0,+1,+2)

Based on the atomic and molecular reaction statics, the ground electronic states of CrH(X⁶Σ⁺), CrH⁺(⁵Σ⁺), CrH²⁺ (⁶Σ⁺) and their dissociation limits have been derived. Using density functional method (B3PW91), 6-311++G^** basis sets for H and split valence polarization basis sets for Cr, the molecular equilibrium geometry and dissociation energies for CrH⁺(⁵Σ⁺) and CrH²⁺ (⁶Σ⁺) have been calculated. The analytical potential energy functions for CrH(X⁶Σ⁺), CrH⁺(⁵Σ⁺) and CrH²⁺ (⁶Σ⁺) are determined. The force fields and spectroscopic parameters have been worked out from these analytical potential energy functions. For the ground state of CrH⁺, the calculated results of R_e, f₂, f₃, f₄, B_e, α_e, ω_e and ω_eχ_e are 0.16200 nm, 1.52574 aJ/nm², -7.81171 aJ/nm³, 28.61613 aJ/nm⁴, 6.71181, 0.28792, 1624.6297 and 53.55394 cm^-1, respectively; and for the ground state of CrH²⁺, the corresponding parameters are 0.24005 nm, 0.42946 aJ/nm², -0.97766 aJ/nm³, 2.40438 aJ/nm⁴, 2.9562, 0.050184, 858.059 and 6.46813 cm^-1, respectively. The theoretical results show minimum points in the potential energy curves of CrH⁺(⁵Σ⁺) and CrH(X⁶Σ⁺), so we conclude that CrH(X⁶Σ⁺) and CrH⁺(⁵Σ⁺) are stable.But there are no minimum points in the potential energy curves of CrH²⁺ (⁶Σ⁺), so CrH²⁺ (⁶Σ⁺) is not stable.