Simplified approach to the mixed time-averaging semiclassical initial value representation for the calculation of dense vibrational spectra
Simplified approach to the mixed time-averaging semiclassical initial value representation for the calculation of dense vibrational spectra
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DOI：
10.1063/1.5020144
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发表时间：
2018-03-21
影响因子：
4.4
通讯作者：
Ceotto, Michele
中科院分区：
文献类型：
--
作者：
Buchholz, Max;Grossmann, Frank;Ceotto, Michele
我们提出并检验了振动光谱半经典计算的一种近似方法。该方法是基于混合时间平均半经典初始值表示方法，它被简化为一种形式，包含一个过滤器，以消除近似谐波环境自由度的贡献。该滤波器没有额外的数值开销，并且对感兴趣的非谐波系统的峰值精度没有负面影响。该方法成功地测试了一个模型的哈密顿量，然后应用到研究的碘在氪矩阵的频率偏移。使用一个层次模型与多达108正常模式包括在计算中，我们展示了如何碘和氪之间的动力学相互作用产生的结果，最低激发碘峰再现实验结果的高度准确性。出版社：AIP Publishing
We present and test an approximate method for the semiclassical calculation of vibrational spectra. The approach is based on the mixed time-averaging semiclassical initial value representation method, which is simplified to a form that contains a filter to remove contributions from approximately harmonic environmental degrees of freedom. This filter comes at no additional numerical cost, and it has no negative effect on the accuracy of peaks from the anharmonic system of interest. The method is successfully tested for a model Hamiltonian and then applied to the study of the frequency shift of iodine in a krypton matrix. Using a hierarchic model with up to 108 normal modes included in the calculation, we show how the dynamical interaction between iodine and krypton yields results for the lowest excited iodine peaks that reproduce experimental findings to a high degree of accuracy. Published by AIP Publishing.