Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan.
J Phys Chem B. 2010 Jan 21;114(2):910-4. doi: 10.1021/jp910362z.
Osawa et al. recently studied density dependence of electronic absorption spectra of p-aminobenzonitrile (ABN) in supercritical and subcritical water. They reported the peak position exhibits a minimum in a specific density. RISM-SCF-SEDD, which is a combination method of ab initio electronic structure theory and a statistical mechanics for molecular liquids, was applied to address the origin of this challenging phenomena. Highly accurate electronic structure theories (CASSCF and MCQDPT2) coupled with microscopic description of hydrogen bonding were employed over a wide range of density condition. We found that the solvation effects on the lower two excited states show different density dependence, suggesting that the turnover is attributed to the difference in sensitivity to solvent of the two states.
最近，Osawa 等人研究了在超临界和亚临界水中对氨基苯甲腈（ABN）的电子吸收光谱的密度依赖性。他们报道说，在特定的密度下，峰位置表现出最小值。RISM-SCF-SEDD 是一种组合了从头算电子结构理论和分子液体统计力学的方法，用于解决这一具有挑战性的现象的起源。在广泛的密度条件下，采用了高度精确的电子结构理论（CASSCF 和 MCQDPT2）和氢键的微观描述。我们发现，较低的两个激发态的溶剂化效应表现出不同的密度依赖性，这表明转折点归因于两个状态对溶剂的敏感性不同。
