物理化学学报( Wuli Huaxue Xuebao)
February
Acta Phys.- Chim. Sin.2011,27(2),379-387
[Article
www.whxb.pku.edu.cn
Sr2*和Ba2水分子体系结构和结合能的从头算和 ABEEM/MM研究
王芳芳2于春阳1刘翠1宮利东'杨忠志1
(辽宁师范大学化学化工学院,辽宁大连116029;济南大学化学化工学院,济南25002)
摘要:应用从头算方法和 ABEEM/MM浮动电荷分子力场,研究了水合碱土离子团簇Sr*/Ba2'(HO)n(n=
1-6)构建了离子-水相互作用的 ABEEM/MM势能函数,获得了水合离子团簇的稳定结构,计算了结合能.计
算结果表明, ABEEM/MM方法的结果和从头算方法的结果有很好的一致性.进一步应用 ABEEM/MM对Sr2*和
Ba2水溶液进行了分子动力学模拟.对SP水溶液,得到的SP?-水中氧原子的径向分布函数的第一和第二最高
峰分别位于0.257和0.464nm处,第一和第二水合层的配位水分子数分别为9.2和11.4;对Ba2'水溶液,得到
的Ba2与水中氧原子的径向分布函数的第一和第二最高峰分别位于0.269和0.467nm处,第一和第二水合层
的配位水分子数分别为9.9和12.4.这与验值或其它论模拟结果有较好的一致性.对比外层的水分子,金
属离子的极化作用使得溶液中第一水合层中水分子的O一H键长增长、HOH键角减小
关键词:水合金属离子团簇;离子溶剂化;从头算方法; ABEEM/MM浮动电荷分子力场;相互作用能
中图分类号:O641
Structures and Binding Energies of Sr/"-water Systems by Ab initio
and ABEEM/MM Method
LIU Yan, WANG Fang-fang 2 YU Chun-yang LIU Cui
Gong Li-dong"YANG Zhong-zhi
(School of Chemistry and Chemical Engineering, Liaoning Normal University, Dalian 116029, Liaoning Province, P. R. China
School of Chemistry and Chemical Engineering, University of Jinan, inan 250022, P R China
Abstract: Hydrated clusters of Sr/Ba(H O)(=1-6)were investigated by the ab initio method and the
ABEEM/MM fluctuatin ch molecular force el. AEMMM potential functions of cation-water
interactions were constructed based on the stable structures and binding energies of the hydrated clusters
were obtained The results from ABEEM/MM are consistent with those from the ab initio method
Furthermore, Sr and Ba aqueous solutions were studied by ABEEM/MM molecular dynamic simulations
Results show that for the Sr aqueous solution the first and second peaks of the Sro radial distribution
function(RDF)are located at 0.257 and 0.464 nm, respectively. The coordination numbers of the water
molecules for the first and second hydration shells are 9.2 and 11.4, respectively. For the Ba aqueous
solution, the first and second peaks of the Bao RDF are located at 0.269 and 0. 467 nm, respectively. The
coordination numbers of water molecules for the first and second hydration shells are 9.9 and 12.4
respectively. These results also show good consistency with experimental observations and other
theoretical simulations. Compared with the external water molecules, the water molecules in the first
hydration shell are evidently polarized by the cation and their O-H bond lengths are stretched while the
HOH bond angles are found to be reduced
Received: October 7, 2010; Revised: December 2, 2010; Published on Web: January 10, 2011
Corresponding author. Email: gongiw(Innu.edu. cn; Tel: +86-411-82158977
The project was supported by the National Natural Science Foundation of China(20633050, 20703022, 2101112007)and Foundation of Education
Bureau of Liaoning Province, China (2009T057)
国家自然科学基金(20633050,20703022,2101120087)和辽字省教育厅基金(20097T057)资助项国
C Editorial office of Acta Physico-chimica Sinica
展开阅读全文