DIALECT, a software package for exciton spectra and dynamics in large molecular assemblies from weak to strong light-matter coupling regimes

TL;DR

DIALECT is a software package that enables detailed simulation of exciton spectra and dynamics in large molecular assemblies, covering weak to strong light-matter coupling regimes, using advanced quantum chemical methodologies.

Contribution

The paper introduces DIALECT, a new software tool that integrates FMO-LC-TDDFTB methods for simulating excited-state properties and dynamics in large molecular systems.

Findings

Successfully simulated energy and charge-transfer processes.

Demonstrated capabilities with trajectory surface hopping and Ehrenfest dynamics.

Calculated polariton dispersion in molecular aggregates.

Abstract

The software package DIALECT is introduced, which provides the capability of calculating excited-state properties and nonadiabatic dynamics of large molecular systems and can be applied to simulate energy and charge-transfer processes in molecular materials. To this end, we employ the FMO-LC-TDDFTB methodology, which combines the use of the fragment molecular orbital approach with the density-functional tight-binding method and an excitonic Hamiltonian including local and charge-transfer excitations. In this work, we present the features and capabilities of the DIALECT software package in simulating the excited state dynamics of molecules and molecular aggregates using exemplary trajectory surface hopping as well as decoherence corrected Ehrenfest dynamics calculations in the framework of LC-TDDFTB and FMO-LC-TDDFTB. In addition, the capability of simulating the polaritonic excited state properties is highlighted by the calculation of the polariton dispersion of an aggregate of naphthalene molecules. The development of the DIALECT program will facilitate the investigation of exciton and charge transport in large and complex molecular systems, such as biological aggregates, nanomaterials and other complex organic molecular systems.