CALCULATION OF VIBRATIONAL FUNDAMENTAL AND OVERTONE BAND INTENSITIES OF H2O
CALCULATION OF VIBRATIONAL FUNDAMENTAL AND OVERTONE BAND INTENSITIES OF H2O
复制标题
H2O 振动基波和泛音带强度的计算
DOI：
10.1063/1.467086
复制
发表时间：
1994
影响因子：
4.4
通讯作者：
M. Sage
中科院分区：
文献类型：
--
作者：
H. Kjaergaard;B. Henry;Huazhou Wei;S. Lefebvre;T. Carrington;O. S. Mortensen;M. Sage
计算了H2O的基频跃迁和泛音跃迁到约18 ，000 cm−1的振动强度。这些强度是由在三个内键坐标下展开的偶极矩函数确定的。展开系数是在6-311G**基组的二阶分子轨道上从头计算的。振动波函数的计算要么是从三维简谐耦合非谐振子(HCAO)模型，该模型使用Morse振子来表示H2O的伸缩和弯曲，要么是从采用最佳可用势能面和精确动能算符的变分计算中得到。为了获得最有意义的振动强度，我们使用ECKART嵌入定义了偶极矩分量。HCAO和变分强度都与实验结果吻合得很好，实验结果跨越了8个数量级。从我们预测的计算中，我们可能会发现……
Vibrational intensities are calculated for the fundamental and overtone transitions of H2O up to approximately 18 000 cm−1. The intensities are determined from a dipole moment function expanded in the three internal bond coordinates. The expansion coefficients are computed ab initio at the second‐order Mo/ller–Plesset level of theory with a 6‐311G** basis set. Vibrational wave functions are calculated either from a three‐dimensional harmonically coupled anharmonic oscillator (HCAO) model which uses Morse oscillators to represent both the stretches and the bend of H2O, or from a variational calculation employing the best available potential energy surface and an exact kinetic energy operator. To obtain the most meaningful vibrational intensities we define dipole moment components using the Eckart embedding. Both the HCAO and the variational intensities agree quite well with the experimental results, which span eight orders of magnitude. From the calculations we predict that it may be possible to detect as ...