AlH自由基在外电场中的分子特性和势能函数

在B3P86/cc-PV5Z水平下,研究了AlH自由基分子在不同外电场中的平衡几何、偶极矩和振动频率等物理性质参数,在此基础上设置合适的外场参数,采用高精度能量计算方法CCSD(T)扫描单点能获得其势能曲线.结果表明物理性质参数和势能值随外电场的变化而变化,且在反向电场中变化幅度较大.利用Morse势模型拟合无外场下势能函数,得到的拟合参数与实验值吻合较好,采用偶极近似构建外电场下的势能函数模型,编制程序拟合对应的势能函数,得出拟合参数,进而计算临界离解电场参量,结果与数值计算值较为一致,说明构建的模型是可靠和准确的.这为分析外场下多原子体系势能面、动力学特性和分子Stark效应冷却囚禁提供重要的理论和实验参考.

Molecular character and potential energy function of AlH free radical under external electric field

Using the density functional B3P86/cc PV5Z method, the geometric structure of AlH molecule under different external electric fields are optimized, and the bond lengths, dipole moments, vibration frequencies and other physical properties parameters are obtained. On the basis of setting appropriate parameters, the scanning single point energies are obtained by CCSD(T) method with the same basis set, and the potential energy curves under different external fields are also obtained. These results show that the physical property parameters and potential energy curves may change with external electric field, especially in the case of reverse direction electric field. The potential energy function without external electric field is fitted by Morse potential, and the fitting parameters are obtained which are in reasonable agreement with experimental values. In order to obtain the critical dissociation electric parameter, the dipole approximation is adopted to construct potential model fitting the corresponding potential energy curve of external electric field. It is found that the fitted critical dissociation electric parameter is consistent with numerical calculation, so that the constructed model is reliable and accurate. These results will provide important theoretical and experimental reference for further studying the potential energy surfaces of multiple atomic, dynamics and molecular cooling with Stark effect.