利用电子结构数据拟合H_2分子的电子壳模型势函数参数

A method of fitting shell model interatomic potential for H_2 molecule from electronic structure data

电子壳模型势函数在离子晶体的原子级计算机模拟中有广泛应用,其势参数主要通过拟合晶体的实验数据或电子结构数据得到.提出了通过拟合双原子分子的量子化学从头计算电子结构数据来获得该势函数的方法,并由H2分子的电子结构数据建立了H原子间的电子壳模型势函数.此外,还应用该势函数对H2+分子离子进行了计算.该势函数拟合方案更适合于共价键型的分子.

The shell model interionic and interatomic potentials are widely used to perform atomistic simulations of ionic crystals. The parameters of the potentials are obtained by fitting the data from measurements and/or electronic structure calculations of the crystal discussed. A new method of fitting shell model interatomic potential is presented for diatomic molecule from electronic structure data obtained by quantum chemical ab initio calculation in the paper. And the shell model interatomic potential for H is fitted from the electronic structure data of H2 molecule for example. To examine the method, the interatomic potential and force of H2^＋ molecular ion are calculated from the potential functions. The results demonstrate that the proposed new fitting procedure shows a fairly good feasibility to the shell model potential for covalent bond molecule.