Department of Chemistry, Iowa State University, Ames, Iowa 50011, USA.
J Chem Phys. 2012 Jul 21;137(3):034116. doi: 10.1063/1.4734314.
Solvent effects on a potential energy surface crossing are investigated by optimizing a conical intersection (CI) in solution. To this end, the analytic energy gradient has been derived and implemented for the collinear spin-flip density functional theory (SFDFT) combined with the effective fragment potential (EFP) solvent model. The new method is applied to the azomethane-water cluster and the chromophore of green fluorescent protein in aqueous solution. These applications illustrate not only dramatic changes in the CI geometries but also strong stabilization of the CI in a polar solvent. Furthermore, the CI geometries obtained by the hybrid SFDFT/EFP scheme reproduce those by the full SFDFT, indicating that the SFDFT/EFP method is an efficient and promising approach for understanding nonadiabatic processes in solution.
通过在溶液中优化锥形交叉（CI）来研究溶剂对势能面交叉的影响。为此，已经推导并实现了用于共线自旋翻转密度泛函理论（SFDFT）与有效片段势（EFP）溶剂模型相结合的解析能量梯度。该新方法应用于偶氮甲烷-水团簇和绿色荧光蛋白的生色团在水溶液中。这些应用不仅说明了 CI 几何形状的剧烈变化，而且还说明了在极性溶剂中 CI 的强烈稳定化。此外，通过混合 SFDFT/EFP 方案获得的 CI 几何形状再现了通过全 SFDFT 获得的那些，这表明 SFDFT/EFP 方法是理解溶液中非绝热过程的有效且有前途的方法。
