基于嵌入原子法的CO-Pt吸附体系的振动光谱计算

Calculation of Vibrational Spectra of CO-Pt Absorption System Based on the Embedded-atom Method

基于CO分子吸附在过渡金属Pt低指数表面的相互作用势模型,采用嵌入原子方法,求解了CO-Pt体系的Schr d inger方程,得到体系的本征振动能量,给出非谐性振动光谱项表达式.结果表明,CO-Pt体系的本征振动仍接近谐振动,但其本征振动能量都比自由态CO分子振动能量小,谱线红移;而且,与势能函数仅取二体势的结果相比,其本征振动能量较大,谱线红移量与文献报道的结果更吻合.

Based on the interaction potential model of CO absorbed on the Pt low-index surfaces, by using the embedded-atom method, both the numerical solution of the Schrǒdinger equation and the eigenvibrational energies of CO - Pt system are obtained, and the anharmonic spectrum expressions are given. The resuits show that the vibrational state of the CO - Pt system is approximate to harmonic oscillation under this model. However, the eigenvibrational energies of CO - Pt system are smaller than that of the free state CO with the red-shift of spectra. Moreover, it is shown that the eigenvibrational energies for potential function including both the embedded-atom energy and the pair potential are larger than that of the potential function only including the pair potential, and the red-shift is closer to those results given by the reports.