Ishikawa Takeshi, Tanaka Kiyoshi
Division of Chemistry, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan.
J Chem Phys. 2005 Feb 15;122(7):074314. doi: 10.1063/1.1851975.
Ab initio calculations were performed to investigate photoinduced transfers among the ground state (GS) and two metastable states (MS1 and MS2) of [Fe(CN)5NO]2-. We obtained the global potential energy surface of the electronic ground state by a scheme of multireference singly and doubly excited configuration interaction followed by a Davidson-type quadruple correction (MRSDCI+Q). The ground state surface has three local minima corresponding to GS, MS1, and MS2. The character of bond between Fe and the nitrosyl group are discussed. We carried out calculations of the lower five electronic excited states by MRSDCI+Q. The main configurations of these lower five excited states were represented by the dFe-->pi*NO transition accompanied by considerable back-donation. The potential energy surfaces of the six states, including the ground state, were obtained by state averaged complete active space self-consistent field calculations. The surfaces have several conical intersections and avoided crossings in the reaction pathway. The photoinduced transfers among GS, MS1, and MS2 are caused by the nonadiabatic effect near these crossings.
进行了从头算计算，以研究[Fe(CN)5NO]2-的基态（GS）和两个亚稳态（MS1和MS2）之间的光致转移。我们通过多参考单重和双重激发组态相互作用方案，随后进行戴维森型四重校正（MRSDCI+Q），获得了电子基态的全局势能面。基态势能面有三个对应于GS、MS1和MS2的局部极小值。讨论了铁与亚硝酰基之间键的性质。我们通过MRSDCI+Q对较低的五个电子激发态进行了计算。这五个较低激发态的主要构型由dFe→π*NO跃迁并伴有大量反馈作用来表示。通过态平均完全活性空间自洽场计算获得了包括基态在内的六个态的势能面。这些势能面在反应路径中有几个锥形交叉点和避免交叉点。GS、MS1和MS2之间的光致转移是由这些交叉点附近的非绝热效应引起的。
