应用从头计算和ABEEMσπ极化力场方法对ML_n(M=Na^+/K^+;L=NMA,H_2O;n=1～6)的研究

Studies on the ML_n(M=Na^+/K^+;L=NMA, H_2O; n=1–6) in terms of quantum chemical method and ABEEMσπ/MM

本文使用从头计算MP2/6-311++G(2d,2p)//B3LYP/6-31+G(d,p)和ABEEM??极化力场(ABEEM??/MM)方法,对MLn(M=Na+/K+;L=N-methlylacetamide,H2O;n=1~6)体系的结构、结合能和电荷分布进行系统研究.研究结果表明,ABEEM??/MM所获得的各种物理量与从头算结果符合很好,其中键长的平均绝对偏差(AAD)接近0.03?,键角的AAD小于0.69°,结合能的AAD小于5%,ABEEM??的电荷分布与从头算的电荷分布的线性相关系数均在0.97以上.

The structures, binding energies and charge distributions of MLn （M=Na^＋/K^＋; L=N-methylacetamide （NMA）, H2O; n=1-6） were studied by high-level quantum chemical methods. In the spirit of atom-bond electronegativity equalization fluctuating charge force field model （ABEEMσπ/MM） and based on high-level quantum chemistry calculations, the interaction potential function for the above systems was constructed. The parameters were optimized and then the molecular potential functions were applied to studies of MLn （M=Na^/K^＋; L=N,N-methylacetamide （NMA）, H2O; n=3-6）. Results show that the performance of ABEEMσπ/MM potential is quite good. Compared with the results from MP2/6-311＋＋G（2d,2p）//B3LYP/6-31＋G（d,p）, the average absolute deviation （AAD） of bond lengths, bond angles, and binding energies from our potential are less than 0.03A, 6.9° and 5%, respectively. The linear correlation coefficients of charge distributions from ABEEM and quantum chemical calculations are above 0.97.