NEXMD v2.0 Software Package for Nonadiabatic Excited State Molecular Dynamics Simulations
Victor M. Freixas, Walter Malone, Xinyang Li, Huajing Song, Hassiel Negrin‐Yuvero, Royle Pérez-Castillo, Alexander White, Tammie Gibson, Dmitry V. Makhov, Dmitrii V. Shalashilin, Yu Zhang, Nikita Fedik, Maksim Kulichenko, Richard A. Messerly, Luke Nambi Mohanam, Sahar Sharifzadeh, Adolfo Bastida, Shaul Mukamel, Sebastian Fernández-Alberti, Sergei Tretiak
Abstract
We present NEXMD version 2.0, the second release of the NEXMD (Nonadiabatic EXcited-state Molecular Dynamics) software package. Across a variety of new features, NEXMD v2.0 incorporates new implementations of two hybrid quantum-classical dynamics methods, namely, Ehrenfest dynamics (EHR) and the Ab-Initio Multiple Cloning sampling technique for Multiconfigurational Ehrenfest quantum dynamics (MCE-AIMC or simply AIMC), which are alternative options to the previously implemented trajectory surface hopping (TSH) method. To illustrate these methodologies, we outline a direct comparison of these three hybrid quantum-classical dynamics methods as implemented in the same NEXMD framework, discussing their weaknesses and strengths, using the modeled photodynamics of a polyphenylene ethylene dendrimer building block as a representative example. We also describe the expanded normal-mode analysis and constraints for both the ground and excited states, newly implemented in the NEXMD v2.0 framework, which allow for a deeper analysis of the main vibrational motions involved in vibronic dynamics. Overall, NEXMD v2.0 expands the range of applications of NEXMD to a larger variety of multichromophore organic molecules and photophysical processes involving quantum coherences and persistent couplings between electronic excited states and nuclear velocity.