北京大学学报自然科学版 ›› 2022, Vol. 58 ›› Issue (5): 785-794.DOI: 10.13209/j.0479-8023.2022.087

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基于密度泛函理论的KDP(100)表面吸附水分子研究

苏鑫杨1, 贺贤土1, 陈军2,†   

  1. 1. 北京大学物理学院应用物理与技术研究中心, 北京 100871 2. 北京应用物理与计算数学研究所, 北京 100088
  • 收稿日期:2021-10-12 修回日期:2021-12-12 出版日期:2022-09-20 发布日期:2022-09-20
  • 通讯作者: 陈军, E-mail: jun_chen(at)iapcm.ac.cn

Study on Adsorption of H2O Molecules on KDP (100) Surface Based on DFT

SU Xinyang1, HE Xiantu1, CHEN Jun2,†   

  1. 1. School of Physics, Peking University, Center for Applied Physics and Technology Beijing 100871 2. Institude of Applied Physics and Comutational Mathematics, Beijing 100088
  • Received:2021-10-12 Revised:2021-12-12 Online:2022-09-20 Published:2022-09-20
  • Contact: CHEN Jun, E-mail: jun_chen(at)iapcm.ac.cn

摘要:

基于密度泛函理论中的第一性原理计算方式, 开展KDP(100)面表面吸附水分子的性质研究。结合Bader电荷、电子密度、差分电子密度和电子局域函数等参数进行电子密度拓扑分析, 结果显示水分子在KDP(100)表面的最佳吸附位点为氢钾桥位, 吸附能为–0.809 eV, 表明 KDP(100)表面可以自发地吸附水分子; 水分子中的氧原子通过吸附, 与KDP(100)表面磷酸根基团上的氢原子形成含共价效应的强氢键O—H...Ow, 拟合键能为–18.88 kcal/mol。

关键词: KDP晶体, 密度泛函理论, 第一性原理分子动力学, 电子密度拓扑分析, 吸附

Abstract:

Based on the calculation method of First-Principles in DFT, the authors carry out the study of the properties of H2O molecules adsorbed on the KDP(100) surface. By topological analysis of the electron density. combining analysis methods such as Bader charge, electron density, electron density difference, electron localization function and other parameters, it is found that the best adsorption site for H2O molecules on KDP(100) surface is H-K bridge site where adsorption energy is –0.809 eV, indicating that the KDP(100) surface can absorb H2O molecules spontaneously. The oxygen atoms in H2O molecules form strong hydrogen bonds O—H...Ow involving covalent effect, with bond energy –18.88 kcal/mol.

Key words: KDP crystal, density functional theory, first-principles molecular dynamics, topological analysis of the electron density, adsorption