Laboratoire de Chimie Physique Moléculaire (LCPM), Ecole Polytechnique Fédérale de Lausanne, Lausanne CH-1015, Switzerland.
J Chem Phys. 2009 Dec 14;131(22):221105. doi: 10.1063/1.3273207.
A joint experimental and first-principles quantum chemical study of the vibration-rotation states of the water molecule up to its first dissociation limit is presented. Triple-resonance, quantum state-selective spectroscopy is used to probe the entire ladder of water's stretching vibrations up to 19 quanta of OH stretch, the last stretching state below dissociation. A new ground state potential energy surface of water is calculated using a large basis set and an all-electron, multireference configuration interaction procedure, which is augmented by relativistic corrections and fitted to a flexible functional form appropriate for a dissociating system. Variational nuclear motion calculations on this surface are used to give vibrational assignments. A total of 44 new vibrational states and 366 rotation-vibration energy levels are characterized; these span the region from 35,508 to 41,126 cm(-1) above the vibrational ground state.
本文对水分子的振动-转动态进行了实验和第一性原理量子化学的联合研究，直至其第一离解极限。采用三重共振、量子态选择光谱技术探测了整个水分子伸缩振动的阶梯，直至 OH 伸缩振动的 19 量子，这是离解以下的最后一个伸缩态。使用大基组和全电子多参考组态相互作用程序计算了水分子的新基态势能面，该势能面通过相对论修正进行了扩充，并拟合了适合离解体系的灵活函数形式。在此表面上进行的变分核运动计算用于给出振动分配。总共描述了 44 个新的振动态和 366 个振转能级；这些状态跨越了从振动基态以上 35508 到 41126 cm(-1)的区域。
