posted on 2020-08-03, 17:08authored byJiří Suchan, Jiří Janoš, Petr Slavíček
Ab initio excited
state photodynamical simulations
have entered the mainstream in the past two decades, bringing techniques
of various sophistication and computational requirements for the description
of nonadiabatic transitions. We explore in this work the performance
of the recently reformulated Landau–Zener surface hopping (LZSH)
approach and extend it for the simultaneous treatment of internal
conversion and intersystem crossing events. We studied photochemical
reactions of four model molecules (cyclopropanone, methaniminium cation,
cytosine, and thiophene). The calculated quantities are generally
in excellent agreement with the corresponding fewest switches surface
hopping simulations. Furthermore, the algorithm proved to be significantly
more stable and more computationally efficient. LZSH also puts fewer
constraints on the electronic structure theory as the nonadiabatic
couplings are not needed. We argue that the accuracy of photodynamical
simulations is in practice dominated by the electronic structure theory,
and it is, therefore, legitimate to use the simplest and the most
efficient technique for the treatment of nonadiabatic transitions.