Influence of Explicit Hydration Waters in Calculating the Hydrolysis Constants for Geochemically Relevant Metals

被引：39

作者：

Wander, Matthew C. F. ^{[1
]}

Rustad, James R. ^{[2
]}

Casey, William H. ^{[2
]}

机构：

[1] Univ Calif Davis, Dept Geol, Davis, CA 95656 USA

[2] Univ Calif Davis, Dept Chem, Davis, CA 95656 USA

来源：

JOURNAL OF PHYSICAL CHEMISTRY A | 2010年 / 114卷 / 04期

基金：

美国国家科学基金会;

关键词：

SOLID-SOLUTION INTERFACE; SOLVATION FREE-ENERGY; AB-INITIO; AQUEOUS-SOLUTION; ELECTRONIC-STRUCTURE; BASIS-SET; CLUSTERS (H2O)(N); PK(A) VALUES; ION; CONTINUUM;

D O I：

10.1021/jp908938p

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The effect of including a second, explicit solvation shell of water molecules is examined on the DFT calculation of a selection of aquo-metal ions' pK(a) values (deprotonation constants). Our goal is to gauge the accuracy of how certain cluster approximations and implicit solvation models (PCM or COSMO) affect the results. The ions in this study include: Al-(aq)(3+); Fe-(aq)(3+); Cr-(aq)(3+); Mn-(aq)(3+); Ga-(aq)(3+); Fe-(aq)(2+); Mg-(aq)(2+); and Be-(aq)(2+). Overall, we find that experimental pK(a) constants call be calculated succcssfully to within 1-2 pH units, provided a consistent hydration structure is maintained for products and reactants.

引用

页码：1917 / 1925

页数：9