School of Chemical Engineering and Advanced Materials, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom.
J Chem Phys. 2009 Nov 28;131(20):204303. doi: 10.1063/1.3259841.
Various all-electron and valence-electron potential energy curves for LiH(X (1)Sigma(+)) are compared and assessed. Hybrid potential energy curves are constructed from all-electron potentials at short range and a valence-electron calculation otherwise. This approach provides for the X state of LiH an overall potential curve, which is ionic at equilibrium, and presents an avoided crossing with the excited A state, leading to neutral dissociation products. The classical turning points predicted by these purely theoretical hybrid potentials are compared with those of the experimentally based inverted-perturbation approach (IPA) potentials for both (7)LiH and (7)LiD. Predicted vibrational energy-level spacings show reasonable (less than or approximately 1 cm(-1)) agreement with the corresponding IPA values. Rotation and vibration-rotation transition energies arising from the most accurate hybrid potential are shown to compare very favorably with recent high-resolution spectroscopic data on (7)LiH and (7)LiD.
比较和评估了 LiH(X (1)Sigma(+))的各种全电子和价电子势能曲线。混合势能曲线由短程的全电子势和其他价电子计算构成。这种方法为 LiH 的 X 态提供了一个整体势能曲线，在平衡时为离子态，并与激发的 A 态发生避免交叉，导致中性解离产物。这些纯理论混合势能预测的经典转折点与基于实验的倒摄位方法（IPA）势能进行比较，IPA 适用于 (7)LiH 和 (7)LiD。预测的振动能级间隔与相应的 IPA 值具有合理的（小于或约 1 cm(-1))一致性。由最准确的混合势能产生的旋转和振转跃迁能量与最近关于 (7)LiH 和 (7)LiD 的高分辨率光谱数据非常吻合。
