Fast Numerical Evaluation of Time-Derivative Nonadiabatic Couplings for Mixed Quantum鈥揅lassical Methods

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• 作者：Ilya G. Ryabinkin ; Jayashree Nagesh ; Artur F. Izmaylov
• 刊名：The Journal of Physical Chemistry Letters
• 出版年：2015
• 出版时间：November 5, 2015
• 年：2015
• 卷：6
• 期：21
• 页码：4200-4203
• 全文大小：250K
• ISSN：1948-7185

文摘

We have developed a numerical differentiation scheme that eliminates evaluation of overlap determinants in calculating the time-derivative nonadiabatic couplings (TDNACs). Evaluation of these determinants was the bottleneck in previous implementations of mixed quantum鈥揷lassical methods using numerical differentiation of electronic wave functions in the Slater determinant representation. The central idea of our approach is, first, to reduce the analytic time derivatives of Slater determinants to time derivatives of molecular orbitals and then to apply a finite-difference formula. Benchmark calculations prove the efficiency of the proposed scheme showing impressive several-order-of-magnitude speedups of the TDNAC calculation step for midsize molecules.