Program for quantum wave-packet dynamics with time-dependent potentials (new version announcement)

Abstract

wavepacket is a program to simulate the dynamics of a wave packet interacting with a time-dependent potential, with the time-dependent Schrödinger equation being solved on a one-, two-, or three-dimensional spatial grid using the split operator method. This new version fixes bugs present in the original program. New version program summaryProgram Title: wavepacketCPC Library link to program files:https://doi.org/10.17632/gnxmkygxrw.1Licensing provisions: GPLv3Programming language: C (iso C99)Journal reference of previous version: Comput. Phys. Commun. 185 (2014) 407–414.Does the new version supersede the previous version?: YesReasons for the new version: Bug fixes.Summary of revisions: This new version fixes bugs in the program wavepacket [1]. In the original version, the function print_wf_bin, used (optionally) to write out the wave function as a binary file, contained a bug that would result in only part of the full wave function being written out when the program was run in parallel.Additionally, negative values of the parameters nt and/or nprint could lead to the program being stuck in an infinite loop. Additional checks have been added to ensure that both these parameters are positive (or zero).Nature of problem: Solves the time-dependent Schrödinger equation for a single particle interacting with a time-dependent potential.Solution method: The wave function is described by its value on a spatial grid and the evolution operator is approximated using the split-operator method [2,3], with the kinetic energy operator calculated using a Fast Fourier Transform.Additional comments including restrictions and unusual features: Simulation can be in one, two, or three dimensions. The fftw [4] implementation of the fast Fourier transform is used, so the corresponding library must be installed. Serial and parallel versions are compiled from the same source files. The parallel version is based on the Message-Passing Interface (mpi) [5].