聚乙烯的杨氏模量及力常数的计算

聚乙烯的杨氏模量及力常数的计算 Calculations of the Young’s Module and Force Constants of Polyethylene 韦荣斌 WEI Rong-bin 1 2 first-author 王小清 WANG Xiao-qing 1 2 邹宪武 ZOU Xian-wu 1 2 金准智 JIN Zhun-zhi 1 2 武汉大学物理科学与技术学院 武汉大学物理科学与技术学院 School of Physics and Technology, Wuhan University School of Physics and Technology, Wuhan University 武汉大学物理科学与技术学院,湖北,武汉,430072 武汉大学物理科学与技术学院,湖北,武汉,430072 用不同于通常的计算力常数的方法,采用适于准一维链的力场,将势能表示为力常数的函数,并用STO 3G基的从头计算方法计算总能,由此求得杨氏模量和力常数.所得结果与实验符合很好,说明这种计算力常数的方法是有效的.所提出的用以拟合聚乙烯能量曲面的表达式能达到很高精度（误差在10-5Hartree左右）,本文为高分子聚合物势能曲面拟合提供了一个简单而有效的方法. A novel method to calculate force constants is developed by using the force field for quasi-one-dimensional chains. The potential energy is a function of the force constants. The total energy is calculated via the ab initio method using the STO-3G base functions. The Young’s module and force constants are derived from the total energy. Our theoretical predictions agree with the experimental results very well, indicating the effectiveness of our new method for force constant calculations. Our fitted formulas for the potential energy surface are extremely accurate with an error around 10 -5 hartree, and can be applied to fitting potential energy surface of other polymer macromolecules.Present study provides a simple and effective method to calculate the Young’s module and force constants of the quasi-one-dimensional polymers. 聚乙烯 从头计算 杨氏模量 力常数 polyethylene ab initio Young’s module force constant TB324 国家自然科学基金资助项目（10274056;10374072） 2004-05-01 2021-04-01 5