Isotope Effects on the Electronic Spectra of Ammonia from Ab Initio Semiclassical Dynamics.

ABSTRACT: Despite its simplicity, the single-trajectory thawed Gaussian approximation has proven useful for calculating the vibrationally resolved electronic spectra of molecules with weakly anharmonic potential energy surfaces. Here, we show that the thawed Gaussian approximation can capture surprisingly well even more subtle observables, such as the isotope effects in the absorption spectra, and we demonstrate it on the four isotopologues of ammonia (NH₃, NDH₂, ND₂H, and ND₃). The differences in their computed spectra are due to the differences in the semiclassical trajectories followed by the four isotopologues, and the isotope effects─narrowing of the transition band and reduction of the peak spacing─are accurately described by this semiclassical metho

SUBMITTER: Kletnieks E 

PROVIDER: S-EPMC10561269 | biostudies-literature | 2023 Oct

REPOSITORIES: biostudies-literature