title: A two-layer approach to the coupled coherent states method.
abstract: In this paper, a two-layer scheme is outlined for the coupled coherent states (CCS) method, dubbed two-layer CCS (2L-CCS). The theoretical framework is motivated by that of the multiconfigurational Ehrenfest method, where different dynamical descriptions are used for different subsystems of a quantum mechanical system. This leads to a flexible representation of the wavefunction, making the method particularly suited to the study of composite systems. It was tested on a 20-dimensional asymmetric system-bath tunnelling problem, with results compared to a benchmark calculation, as well as existing CCS, matching-pursuit/split-operator Fourier transform, and configuration interaction expansion methods. The two-layer method was found to lead to improved short and long term propagation over standard CCS, alongside improved numerical efficiency and parallel scalability. These promising results provide impetus for future development of the method for on-the-fly direct dynamics calculations.
authors.affiliation: School of Chemistry, University of Leeds, Leeds LS2 9JT, United Kingdom.
authors.forename: James A
authors.initials: JA
authors.lastname: Green
authors.affiliation: Instituto de Física "Gleb Wataghin," Universidade Estadual de Campinas, 13083-859 Campinas, SP, Brazil.
authors.forename: Adriano
authors.initials: A
authors.lastname: Grigolo
authors.affiliation: School of Chemistry, University of Leeds, Leeds LS2 9JT, United Kingdom.
authors.forename: Miklos
authors.initials: M
authors.lastname: Ronto
authors.affiliation: School of Chemistry, University of Leeds, Leeds LS2 9JT, United Kingdom.
authors.forename: Dmitrii V
authors.initials: DV
authors.lastname: Shalashilin