On-the-fly ab initio three thawed Gaussians approximation: A semiclassical approach to Herzberg-Teller spectra

Abstract

Evaluation of symmetry-forbidden or weakly-allowed vibronic spectra requires treating the transition dipole moment beyond the Condon approximation. To include vibronic spectral features not captured in the global harmonic models, we have recently implemented an on-the-fly ab initio extended thawed Gaussian approximation, where the propagated wavepacket is a Gaussian multiplied by a linear polynomial. To include more anharmonic effects, here we represent the initial wavepacket by a superposition of three independent Gaussian wavepackets - one for the Condon term and two displaced Gaussians for the Herzberg-Teller part. Application of this ab initio "three thawed Gaussians approximation" to vibrationally resolved electronic spectra of the phenyl radical and benzene shows a clear improvement over the global harmonic and Condon approximations. The orientational averaging of spectra, the relation between the gradient of the transition dipole moment and nonadiabatic coupling vectors, and the details of the extended and three thawed Gaussians approximation are discussed.

Final form available via open access in Chem. Phys. at https://www.sciencedirect.com/science/article/pii/S0301010418306220

References in corpus (8)

• Modelling of Oscillations in Two-Dimensional Echo-Spectra of the Fenna-Matthews-Olson Complex
• First-Principles Semiclassical Initial Value Representation Molecular Dynamics
• Semiclassical "Divide-and-Conquer" Method for Spectroscopic Calculations of High Dimensional Molecular Systems
• On-the-fly ab initio semiclassical dynamics: Identifying degrees of freedom essential for emission spectra of oligothiophenes
• On-the-fly ab initio semiclassical evaluation of absorption spectra of polyatomic molecules beyond the Condon approximation
• Simplified Approach to the Mixed Time-averaging Semiclassical Initial Value Representation for the Calculation of Dense Vibrational Spectra
• UV spectra of benzene isotopomers and dimers in helium nanodroplets
• Beating the efficiency of both quantum and classical simulations with semiclassics

Cited by in corpus (20)

• Machine learning for electronically excited states of molecules
• Single-Hessian thawed Gaussian approximation: The missing rung on the ladder
• Semiclassical Approach to Photophysics Beyond Kasha's Rule and Vibronic Spectroscopy Beyond the Condon Approximation. The Case of Azulene
• On-the-fly ab initio semiclassical evaluation of vibronic spectra at finite temperature
• Core-valence attosecond transient absorption spectroscopy of polyatomic molecules
• On-the-fly ab initio semiclassical evaluation of time-resolved electronic spectra
• An Effective Semiclassical Approach to IR Spectroscopy
• On-the-fly ab initio semiclassical evaluation of third-order response functions for two-dimensional electronic spectroscopy
• Vibrational Investigation of Nucleobases by Means of Divide and Conquer Semiclassical Dynamics
• Search for long lasting electronic coherence using on-the-fly ab initio semiclassical dynamics
• Internal Conversion Rates from the Extended Thawed Gaussian Approximation: Theory and Validation
• A time-reversible integrator for the time-dependent Schrödinger equation on an adaptive grid
• Temperature and Tautomeric Effects in High-Resolution Oxygen 1s X-ray Photoelectron Spectroscopy of Purines and Pyrimidines
• Exciton Transfer Using Rates Extracted From the "Hierarchical Equations of Motion''
• Single vibronic level fluorescence spectra from Hagedorn wavepacket dynamics
• Isotope effects in the electronic spectra of ammonia from ab initio semiclassical dynamics
• Prediction of Fluorescence Quantum Yields using the Extended Thawed Gaussian Approximation
• Simulating Molecular Single Vibronic Level Fluorescence Spectra with ab initio Hagedorn Wavepacket Dynamics
• Refined approach to cellularization: going from Heller's thawed Gaussian approximation to the Herman--Kluk propagator
• On the single-Hessian Gaussian wavepacket dynamics