Linear and Nonlinear Optical Properties of Molecules from Real-Time Propagation Based on the Bethe-Salpeter Equation

Abstract

We present a real-time propagation method for computing linear and nonlinear optical properties of molecules based on the Bethe-Salpeter equation. The method follows the time evolution of the one-particle density matrix under an external electric field. We include electron-electron interaction effects through a self-energy based on the screened exchange approximation. Quasiparticle energies are taken from a prior $GW$ calculation to construct the effective single-particle Hamiltonian and we represent all operators and wavefunctions in an atom-centered Gaussian basis. We benchmark the accuracy of the real-time propagation against the standard linear-response Bethe-Salpeter equation using a set of organic molecules. We find very good agreement when computing linear-response isotropic polarizability spectra from both approaches, with a mean absolute deviation of 30~meV in peak positions. Beyond linear response, we simulate second harmonic generation and optical rectification in a non-centrosymmetric molecule. These phenomena are not captured by the commonly used linear-response Bethe-Salpeter equation. We foresee broad applicability of real-time propagation based on the Bethe-Salpeter equation for the study of linear and nonlinear optical properties of molecules as the method has a similar computational cost as time-dependent density functional theory with hybrid functionals.

References in corpus (17)

• Many-body perturbation theory calculations using the yambo code
• The GW compendium: A practical guide to theoretical photoemission spectroscopy
• The Bethe-Salpeter Equation Formalism: From Physics to Chemistry
• Cubic scaling $GW$: towards fast quasiparticle calculations
• Excited States From State Specific Orbital Optimized Pair Coupled Cluster
• Low-scaling $GW$ with benchmark accuracy and application to phosphorene nanosheets
• Variational coupled cluster for ground and excited states
• Nonlinear optical selection rules of excitons in monolayer transition metal dichalcogenides
• Reference Energies for Valence Ionizations and Satellite Transitions
• Reference CC3 Excitation Energies for Organic Chromophores: Benchmarking TD-DFT, BSE/$GW$ and Wave Function Methods
• Valley Polarization-Electric Dipole Interference and Nonlinear Chiral Selection Rules in Monolayer WSe${}_2$
• Electronic transport in molecular junctions: The generalized Kadanoff-Baym ansatz with initial contact and correlations
• Linear Scaling Density Matrix Real Time TDDFT: Propagator Unitarity \& Matrix Truncation
• Exciton enhanced nonlinear optical responses in monolayer h-BN and MoS2: Insight from first-principles exciton-state coupling formalism and calculations
• Low-scaling GW algorithm applied to twisted transition-metal dichalcogenide heterobilayers
• Spin-orbit torque in single-molecule junctions from ab initio
• Anomalous propagators and the particle-particle channel: Bethe-Salpeter equation

Cited by in corpus (2)

• Optical spectra of small silver clusters with the Bethe-Salpeter formalism: a Reassessment
• Optical excitations in nanographenes from the Bethe-Salpeter equation and time-dependent density functional theory: absorption spectra and spatial descriptors