Molecular Double Core Hole Electron Spectroscopy of Nucleobases
Molecular Double Core Hole Electron Spectroscopy of Nucleobases
复制标题
核碱基分子双核孔电子能谱
DOI：
10.1021/jp205923m
复制
发表时间：
2011
期刊：
影响因子：
--
通讯作者：
K. Ueda
中科院分区：
文献类型：
--
作者：
O. Takahashi;M. Tashiro;M. Ehara;K. Yamasaki;K. Ueda
用密度泛函理论（DFT）方法研究了嘧啶、嘌呤、RNA/DNA核碱基和甲酰胺的双核空穴（DCH）光谱。用完全活性空间自洽场（CASSCF）方法研究了甲酰胺的DCH谱。计算了核碱基的所有可能的单位点和双位点DCH（ssDCH和tsDCH）状态。广义弛豫能和原子间广义弛豫能分别从ssDCH和单芯空穴（SCH）态之间的能量差和tsDCH和SCH态之间的能量差进行评估。广义弛豫能与自然键轨道电荷相关，而原子间广义弛豫能与两个中心空穴的原子间距离相关。用DCH光谱分析表明，该方法对大分子体系的化学分析是有用的。
Double-core-hole (DCH) spectra have been investigated for pyrimidine, purine, the RNA/DNA nucleobases, and formamide, using the density functional theory (DFT) method. DCH spectra of formamide were also examined by the complete-active-space self-consistent-field (CASSCF) method. All possible single- and two-site DCH (ssDCH and tsDCH) states of the nucleobases were calculated. The generalized relaxation energy and interatomic generalized relaxation energy were evaluated from the energy differences between ssDCH and single-core-hole (SCH) states and between tsDCH and SCH states, respectively. The generalized relaxation energy is correlated to natural bond orbital charge, whereas the interatomic generalized relaxation energy is correlated to the interatomic distance between the core holes at two sites. The present analysis using DCH spectroscopy demonstrates that the method is useful for the chemical analysis of large molecular systems.