Sr2+和Ba2+水分子體系結(jié)構(gòu)和結(jié)合能的從頭算和ABEEM/MM研究
作者：Yan Liu, Fang-Fang Wang, Chun-Yang Yu, Cui Liu, Li-Dong Gong*, Zhong-Zhi Yang
關(guān)鍵字：Hydrated metal cation cluster,Ion solvation,Ab initio method,ABEEM/MM fluctuating charge molecular force field,Interaction energy
論文來源：期刊
具體來源：Acta Phys. –Chim. Sin. 2011, 27, 379-387.
發(fā)表時間：2011年
Hydrated clusters of Sr2+/Ba2+(H2O)n (n=1-6) were investigated by theab initiomethod and the ABEEM/MM fluctuating charge molecular force field. ABEEM/MM 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 theab initio method. Furthermore, Sr2+ and Ba2+ aqueous solutions were studied by ABEEM/MM molecular dynamic simulations. Results show that for the Sr2+ aqueous solution the first and second peaks of the SrO radial distribution function (RDF) are located at 0.257and0.464nm, respectively. The coordination numbers of the water molecules for the first and second hydration shells are9.2and11.4, respectively. For the Ba2+ aqueous solution, the first and second peaks of the BaO RDF are located at 0.269 and 0.467nm, 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 anglesare found to be reduced.