物理化学学报 >> 1995, Vol. 11 >> Issue (06): 509-515.doi: 10.3866/PKU.WHXB19950607

研究论文 上一篇    下一篇

液态水热容的量子校正

顾健德,Muhammad Ashraf Khan,田安民,鄢国森   

  1. 四川大学化学系|成都 610064
  • 收稿日期:1994-01-27 修回日期:1994-10-18 发布日期:1995-06-15
  • 通讯作者: 田安民

Quantum Correction for the Heat Capacity of Liquid Water

Gu Jian-De,Muhammad Ashraf Khan,Tian An-Min,Yan Guo-Sen   

  1. Department of Chemistry,Sichuan University,Chengdu 610064
  • Received:1994-01-27 Revised:1994-10-18 Published:1995-06-15
  • Contact: Tian An-Min

摘要:

在不同温度下对液态水进行分子动力学模拟,研究各温度下液态水中各个原子的速度自相关函数密度谱,以考察液态水热容的量子校正随温度的变化规律.研究结果表明,水分子的三个内部振动模式对热容的量子校正不随温度变化,而转动和分子距平衡位置的摆动运动模式的量子校正随温度升高而逐步减小.对于分子动力学模拟结果经温度涨落计算所得的热容进行了量子校正,校正结果与实验值能符合.

关键词: 热容, 量子校正, MD模拟, 速度自相关, 液态水

Abstract:

To investigate the influences of temperature on the quantum correction for heat capacity of liquid water, molecular dynamics simulations for liquid water were performed and the spectra of velocity autocorrelation function for the atoms were calculated under different temperatures. The study shows that the quantum correction for heat capacity for the three intramolecular vibration modes keeps almost unchanged while the corrections for rotation and libration modes decrease as temperature increases. Corrections were made for the classical heat capacities calculated as the fluctuations of the temperature during the molecular dynamics simulations for liquid water. The corrected results agree well to those from experiments.

Key words: Heat capacity, Quantum correction, MD simulation, Velocity autocorrelation, Liquid water