Büchel Ralf, Álvarez Luis, Grage Jan, Maniscalco Dominykas, Frank Irmgard
Theoretical Chemistry, Leibniz University Hannover, Callinstr. 3A, 30167 Hannover, Germany.
Molecules. 2024 Sep 23;29(18):4509. doi: 10.3390/molecules29184509.
It is a well-established standard to describe ground-state chemical reactions at an ab initio level of multi-electron theory. Fast reactions can be directly simulated. The most widely used approach is density functional theory for the electronic structure in combination with molecular dynamics for the nuclear motion. This approach is known as ab initio molecular dynamics. In contrast, the simulation of excited-state reactions at this level of theory is significantly more difficult. It turns out that the self-consistent solution of the Kohn-Sham equations is not easily reached in excited-state simulations. The first program that solved this problem was the Car-Parrinello molecular dynamics code, using restricted open-shell Kohn-Sham theory. Meanwhile, there are alternatives, most prominently the Q-Chem code, which widens the range of applications. The present study investigates the suitability of both codes for the molecular dynamics simulation of excited-state motion and presents applications to photoreactions.
在多电子理论的从头算水平上描述基态化学反应是一个成熟的标准。快速反应可以直接模拟。最广泛使用的方法是将用于电子结构的密度泛函理论与用于核运动的分子动力学相结合。这种方法被称为从头算分子动力学。相比之下，在这个理论水平上模拟激发态反应要困难得多。事实证明，在激发态模拟中不容易达到Kohn-Sham方程的自洽解。第一个解决这个问题的程序是Car-Parrinello分子动力学代码，它使用受限开壳Kohn-Sham理论。与此同时，还有其他选择，最突出的是Q-Chem代码，它拓宽了应用范围。本研究调查了这两种代码对激发态运动分子动力学模拟的适用性，并展示了其在光反应中的应用。
