First-principles prediction and partial characterization of the vibrational states of water up to dissociation
First-principles prediction and partial characterization of the vibrational states of water up to dissociation
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DOI：
10.1016/j.jqsrt.2010.02.009
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发表时间：
2010-06-01
影响因子：
2.3
通讯作者：
Tennyson, Jonathan
中科院分区：
文献类型：
--
作者：
Csaszar, Attila G.;Matyus, Edit;Tennyson, Jonathan
提出了一种新的、精确的、全局的、与质量无关的、第一性原理的水分子基态势能面。PES是基于在电子结构理论的全电子aug-cc-pCV 6 Z IC-MRCI（8，2）水平上计算的2200个能量点，包括相对论单电子质量速度和达尔文修正。对于H2O 16，PES的离解能D-0 = 41109 cm（-1），支持1150个振动能级，最高可达41083 cm（-1）.对于能量小于39000 cm（-1）的所有态，计算的能级与实验测量的能级之间的偏差小于15 cm（-1）。近似振动量子数的表征是使用几种技术：能量分解，波函数图，正常模式分布，内部坐标的平方的期望值，和扰动的PES的弯曲部分。振动简正模标签，虽然通常没有物理意义，已被分配到所有低于26 500 cm（-1）的状态和更多的高于它，包括一些高度激发的拉伸状态，一直到解离。讨论了与计算高激发态振动带强度有关的问题。(C)2010爱思唯尔有限公司保留所有权利。
A new, accurate, global, mass-independent, first-principles potential energy surface (PES) is presented for the ground electronic state of the water molecule. The PES is based on 2200 energy points computed at the all-electron aug-cc-pCV6Z IC-MRCI(8,2) level of electronic structure theory and includes the relativistic one-electron mass-velocity and Darwin corrections. For H-2 O-16, the PES has a dissociation energy of D-0 = 41 109 cm(-1) and supports 1150 vibrational energy levels up to 41 083 cm(-1). The deviation between the computed and the experimentally measured energy levels is below 15 cm(-1) for all the states with energies less than 39000 cm(-1). Characterization of approximate vibrational quantum numbers is performed using several techniques: energy decomposition, wave function plots, normal mode distribution, expectation values of the squares of internal coordinates, and perturbing the bending part of the PES. Vibrational normal mode labels, though often not physically meaningful, have been assigned to all the states below 26 500 cm(-1) and to many more above it, including some highly excited stretching states all the way to dissociation. Issues to do with calculating vibrational band intensities for the higher-lying states are discussed. (C) 2010 Elsevier Ltd. All rights reserved.