Analytical State-Average Complete-Active-Space Self-Consistent Field Nonadiabatic Coupling Vectors: Implementation with Density-Fitted Two-Electron Integrals and Application to Conical Intersections

详细信息    查看全文

• 作者：Ignacio Fdez. Galván ; Mickaël G. Delcey ; Thomas Bondo Pedersen ; Francesco Aquilante ; Roland Lindh
• 刊名：Journal of Chemical Theory and Computation
• 出版年：2016
• 出版时间：August 9, 2016
• 年：2016
• 卷：12
• 期：8
• 页码：3636-3653
• 全文大小：1001K
• 年卷期：0
• ISSN：1549-9626

文摘

Analytical state-average complete-active-space self-consistent field derivative (nonadiabatic) coupling vectors are implemented. Existing formulations are modified such that the implementation is compatible with Cholesky-based density fitting of two-electron integrals, which results in efficient calculations especially with large basis sets. Using analytical nonadiabatic coupling vectors, the optimization of conical intersections is implemented within the projected constrained optimization method. The standard description and characterization of conical intersections is reviewed and clarified, and a practical and unambiguous system for their classification and interpretation is put forward. These new tools are subsequently tested and benchmarked for 19 different conical intersections. The accuracy of the derivative coupling vectors is validated, and the information that can be drawn from the proposed characterization is discussed, demonstrating its usefulness.