Abstract
Diabatization converts adiabatic electronic states to diabatic states, which can be fit with smooth functions, thereby decreasing the computational time for simulations. Here we present a new diabatization scheme based on components of the nonadiabatic couplings and the adiabatic energy gradients. The nonadiabatic couplings are multi-dimensional vectors that are singular along conical intersection seams, and this makes them essentially impossible to fit; furthermore they have unphysical aspects due to the assumptions of the generalized Born-Oppenheimer scheme, and therefore they are not usually used in diabatization schemes. However, we show here that the nonadiabatic couplings can provide a route to obtaining diabatic states by using the sign change of the energy gradient differences of adiabatic states on paths through conical intersections or locally avoided crossings. We present examples applying the method successfully to several test systems. We compare the method to other diabatization methods previously developed in our group.
Original language | English (US) |
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Pages (from-to) | 26643-26659 |
Number of pages | 17 |
Journal | Physical Chemistry Chemical Physics |
Volume | 20 |
Issue number | 41 |
DOIs | |
State | Published - 2018 |
Bibliographical note
Funding Information:The computational resources were provided by the University of Minnesota Supercomputing Institute and by the Department of Aerospace Engineering and Mechanics at University of Minnesota. This work was supported in part by the Air Force Office of Scientific Research under grant no. FA9550-16-1-0161.
Funding Information:
We thank Yinan Shu, Yuliya Paukku, Sijia Dong, Hans-Joachim Werner, David Yarkony, and the late Steven L. Mielke for helpful discussions or email during the method development. The computational resources were provided by the University of Minnesota Supercomputing Institute and by the Department of Aerospace Engineering and Mechanics at University of Minnesota. This work was supported in part by the Air Force Office of Scientific Research under grant no. FA9550-16-1-0161.
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