From microhydration to bulk hydration of Sr²⁺ metal ion: DFT, MP2 and molecular dynamics study

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• 作者：Anil Boda ; Sulagna De ; Sk. Musharaf Ali ; Srinivas Tulishetti ; S ; ip Khan ; Jayant K. Singh
• 关键词：Microhydration ; Strontium ; DFT ; MP2 ; MD ; EXAFS
• 刊名：Journal of Molecular Liquids
• 出版年：2012
• 出版时间：August, 2012
• 年：2012
• 卷：172
• 期：Complete
• 页码：110-118
• 全文大小：769 K

文摘

This paper presents the results of quantum chemical and classical molecular dynamics (MD) simulations of the microhydration states of the Sr²⁺ ion. The quantum chemical results strongly suggest a coordination number (CN) of 8 for the first hydration shell of Sr²⁺, which is in quantitative agreement with data available from X-ray absorption fine structure (XAFS) measurements. The calculated theoretical SrO bond distance of 2.59 ? is also in excellent agreement with the XAFS results (2.60 ?). Classical MD simulations are conducted on various water models to predict the hydration structure of the Sr²⁺ ion. The CN is found to be in the range of 8-9 using SPC, TIP3P, and TIP4P-2005 water models, with the probability more skewed toward 8. MD-EXAFS study and coordination number analyses reveal that TIP4P-2005 is the best model potential for simulating water molecules to reproduce the experimentally observed absorption spectra and coordination numbers.