Combined Surface-Hopping, Dyson Orbital, and B-Spline Approach for the Computation of Time-Resolved Photoelectron Spectroscopy Signals: The Internal Conversion in Pyrazine

Piteša, Tomislav; Sapunar, Marin; Ponzi, Aurora; Gelin, Maxim F.; Došlić, Nađa; Domcke, Wolfgang; Decleva, Piero (2021) Combined Surface-Hopping, Dyson Orbital, and B-Spline Approach for the Computation of Time-Resolved Photoelectron Spectroscopy Signals: The Internal Conversion in Pyrazine. Journal of Chemical Theory and Computation, 17 (8). pp. 5098-5109. ISSN 1549-9618

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Official URL: http://doi.org/10.1021/acs.jctc.1c00396

Abstract

A computational protocol for simulating time-resolved photoelectron signals of medium-sized molecules is presented. The procedure is based on a trajectory surface-hopping description of the excited-state dynamics and a combined Dyson orbital and multicenter B-spline approach for the computation of cross sections and asymmetry parameters. The accuracy of the procedure has been illustrated for the case of ultrafast internal conversion of gas-phase pyrazine excited to the 1B2u(ππ*) state. The simulated spectra and the asymmetry map are compared to the experimental data, and a very good agreement was obtained without applying any energy-dependent rescaling or broadening. An interesting side result of this work is the finding that the signature of the 1Au(nπ*) state is indistinguishable from that of the 1B3u(nπ*) state in the time-resolved photoelectron spectrum. By locating four symmetrically equivalent minima on the lowest-excited (S1) adiabatic potential energy surface of pyrazine, we revealed the strong vibronic coupling of the 1Au(nπ*) and 1B3u(nπ*) states near the S1 ← S0 band origin.

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Article

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This document is the unedited Author’s version of a Submitted Manuscript subsequently accepted for publication in Journal of Chemical Theory and Computation, copyright © 2021 American Chemical Society. To access the final published article, see ACS Articles on Request.

Uncontrolled Keywords:

trajectory surface hopping ; nonadiabatic dynamics ; photochemistry

Subjects:

NATURAL SCIENCES > Chemistry > Theoretical Chemistry

Divisions:

Division of Physical Chemistry

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