Effect of solvation on the vertical ionization energy of thymine: from microhydration to bulk.
Effect of solvation on the vertical ionization energy of thymine: from microhydration to bulk.
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DOI：
10.1021/jp110438c
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发表时间：
2011-06-16
影响因子：
2.9
通讯作者：
Krylov, Anna I.
中科院分区：
文献类型：
--
作者：
Ghosh, Debashree;Isayev, Olexandr;Slipchenko, Lyudmila V.;Krylov, Anna I.
采用运动方程电离势耦合团簇（EOM-IP-CCSD）和有效碎片势（EFP）方法研究了水合对胸腺嘧啶垂直电离能（VIE）的影响。我们考虑了几个微溶剂化的集群，以及在散装水溶剂化的胸腺嘧啶。通过对300 K下平衡MD轨迹得到的溶剂-溶质构型进行平均，计算了本体水中的VIE。分析了微溶剂化的影响，并与第一溶剂化壳在本体水中的组合效应进行了对比。微溶剂化使每个水分子的电离能（IE）降低约0.1 eV，而第一溶剂化壳使IE增加0.1 eV。随后的溶剂化降低了IE，溶剂诱导的胸腺嘧啶VIE位移的体积值约为−0.9 eV。第一溶剂化壳层的组合效应被解释在特定的溶质-溶剂相互作用，这是使用模型的几何形状进行了研究。IE收敛到体积值需要约13.5 μ m半径的水化球。EOM-IP-CCSD/EFP方案的性能与使用微水合结构的完全EOM-IP-CCSD进行基准测试。误差小于0.01- 0.02eV。研究了极化和高阶多极矩在EFP模型中的相对重要性。
The effect of hydration on the vertical ionization energy (VIE) of thymine was characterized using equation-of-motion ionization potential coupled-cluster (EOM-IP-CCSD) and effective fragment potential (EFP) methods. We considered several microsolvated clusters as well as thymine solvated in bulk water. The VIE in bulk water was computed by averaging over solvent-solute configurations obtained from equilibrium MD trajectories at 300 K. The effect of microsolvation was analyzed and contrasted against the combined effect of the first solvation shell in bulk water. Microsolvation reduces the ionization energy (IE) by about 0.1 eV per water molecule while the first solvation shell increases the IE by 0.1 eV. The subsequent solvation lowers the IE, and the bulk value of the solvent-induced shift of thymine’s VIE is approximately −0.9 eV. The combined effect of the first solvation shell was explained in terms of specific solute-solvent interactions, which were investigated using model geometries. The convergence of IE to the bulk value requires the hydration sphere of approximately 13.5 Å radius. The performance of the EOM-IP-CCSD/EFP scheme was benchmarked against full EOM-IP-CCSD using microhydrated structures. The errors were found to be less than 0.01–0.02 eV. The relative importance of the polarization and higher multipole moments in EFP model was also investigated.
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影响因子：
2.9
作者：
Gordon, MS;Freitag, MA;Stevens, WJ
通讯作者：
Stevens, WJ
影响因子：
4.4
作者：
Jensen, JH
通讯作者：
Jensen, JH
影响因子：
4.4
作者：
JORGENSEN, WL;CHANDRASEKHAR, J;KLEIN, ML
通讯作者：
KLEIN, ML
影响因子：
4.4
作者：
ESSMANN, U;PERERA, L;PEDERSEN, LG
通讯作者：
PEDERSEN, LG
DOI：
10.1016/s1574-1400(07)03010-1
发表时间：
2007-01-01
期刊：
ANNUAL REPORTS IN COMPUTATIONAL CHEMISTRY, VOL 3
影响因子：
--
作者：
Gordon, Mark S.;Slipchenko, Lyudmilla;Jensen, Jan H.
通讯作者：
Jensen, Jan H.