U.S. Department of Energy Office of Scientific and Technical Information
Enabling complete multichannel nonadiabatic dynamics: A global representation of the two-channel coupled, 1,21A and 13A states of NH3 using neural networks
Global coupled three-state two-channel potential energy and property/interaction (dipole and spin–orbit coupling) surfaces for the dissociation of NH3(Ã) into NH + H2 and NH2 + H are reported. The permutational invariant polynomial-neural network approach is used to simultaneously fit and diabatize the electronic Hamiltonian by fitting the energies, energy gradients, and derivative couplings of the two coupled lowest-lying singlet states as well as fitting the energy and energy gradients of the lowest-lying triplet state. The key issue in fitting property matrix elements in the diabatic basis is that the diabatic surfaces must be smooth, that is, the diabatization must remove spikes in the original adiabatic property surfaces attributable to the switch of electronic wavefunctions at the conical intersection seam. Here, we employ the fit potential energy matrix to transform properties in the adiabatic representation to a quasi-diabatic representation and remove the discontinuity near the conical intersection seam. The property matrix elements can then be fit with smooth neural network functions. The coupled potential energy surfaces along with the dipole and spin–orbit coupling surfaces will enable more accurate and complete treatment of optical transitions, as well as nonadiabatic internal conversion and intersystem crossing.
Wang, Yuchen, et al. "Enabling complete multichannel nonadiabatic dynamics: A global representation of the two-channel coupled, 1,2<sup>1</sup>A and 1<sup>3</sup>A states of NH<sub>3</sub> using neural networks." Journal of Chemical Physics, vol. 154, no. 9, Mar. 2021. https://doi.org/10.1063/5.0037684
Wang, Yuchen, Guan, Yafu, Guo, Hua, & Yarkony, David R. (2021). Enabling complete multichannel nonadiabatic dynamics: A global representation of the two-channel coupled, 1,2<sup>1</sup>A and 1<sup>3</sup>A states of NH<sub>3</sub> using neural networks. Journal of Chemical Physics, 154(9). https://doi.org/10.1063/5.0037684
Wang, Yuchen, Guan, Yafu, Guo, Hua, et al., "Enabling complete multichannel nonadiabatic dynamics: A global representation of the two-channel coupled, 1,2<sup>1</sup>A and 1<sup>3</sup>A states of NH<sub>3</sub> using neural networks," Journal of Chemical Physics 154, no. 9 (2021), https://doi.org/10.1063/5.0037684
@article{osti_1852059,
author = {Wang, Yuchen and Guan, Yafu and Guo, Hua and Yarkony, David R.},
title = {Enabling complete multichannel nonadiabatic dynamics: A global representation of the two-channel coupled, 1,2<sup>1</sup>A and 1<sup>3</sup>A states of NH<sub>3</sub> using neural networks},
annote = {Global coupled three-state two-channel potential energy and property/interaction (dipole and spin–orbit coupling) surfaces for the dissociation of NH3(Ã) into NH + H2 and NH2 + H are reported. The permutational invariant polynomial-neural network approach is used to simultaneously fit and diabatize the electronic Hamiltonian by fitting the energies, energy gradients, and derivative couplings of the two coupled lowest-lying singlet states as well as fitting the energy and energy gradients of the lowest-lying triplet state. The key issue in fitting property matrix elements in the diabatic basis is that the diabatic surfaces must be smooth, that is, the diabatization must remove spikes in the original adiabatic property surfaces attributable to the switch of electronic wavefunctions at the conical intersection seam. Here, we employ the fit potential energy matrix to transform properties in the adiabatic representation to a quasi-diabatic representation and remove the discontinuity near the conical intersection seam. The property matrix elements can then be fit with smooth neural network functions. The coupled potential energy surfaces along with the dipole and spin–orbit coupling surfaces will enable more accurate and complete treatment of optical transitions, as well as nonadiabatic internal conversion and intersystem crossing.},
doi = {10.1063/5.0037684},
url = {https://www.osti.gov/biblio/1852059},
journal = {Journal of Chemical Physics},
issn = {ISSN 0021-9606},
number = {9},
volume = {154},
place = {United States},
publisher = {American Institute of Physics (AIP)},
year = {2021},
month = {03}}