常用分子間相互作用勢(shì)函數(shù)~Morse勢(shì)函數(shù)
2022-08-24 11:08 作者:邱新龍分子模擬小破屋 | 我要投稿
Morse勢(shì)函數(shù)具有三個(gè)勢(shì)參數(shù),其中Dc和r0分別對(duì)應(yīng)Lennard-Jones勢(shì)函數(shù)的兩個(gè)參數(shù),β不與任何Lennard-Jones參數(shù)對(duì)應(yīng),

事實(shí)上,β參數(shù)的作用是控制勢(shì)函數(shù)的平坦程度,與Lennard-Jonesn~m勢(shì)函數(shù)的n和m參數(shù)對(duì)應(yīng),調(diào)整β參數(shù),可以得到與不同n和m對(duì)應(yīng)的勢(shì)函數(shù)。例如,與Lennard-Jones12-6勢(shì)函數(shù)對(duì)應(yīng)的平衡距離為1.1225δ, β/r0=6.00;相應(yīng)的勢(shì)函數(shù)和力函數(shù)的對(duì)比如圖3-5所示。從圖中可以看出,在勢(shì)阱附近,兩類不同的勢(shì)函數(shù)幾乎重合。這兩類勢(shì)函數(shù)最大的差別在最大作用附近,Morse勢(shì)函數(shù)比較陡,其最大吸引力比對(duì)應(yīng)的Lennard-Jones勢(shì)函數(shù)大。與常見Lennard-Jonesn-m勢(shì)函數(shù)對(duì)應(yīng)的Morse勢(shì)參數(shù)列于表3-1。



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