PyPI Conda

dynasor – Correlations for everyone

dynasor is a tool for calculating total and partial dynamic structure factors as well as related correlation functions from molecular dynamics (MD) simulations. Analysis of these functions enables one to access the dynamics of a system without resorting to perturbative approaches. By combining in particular the structure factor with the cross sections (or form factors) of, e.g., neutrons, X-rays or electrons, it is also possible to directly predict experimental spectra.

Specifically dynasor can be used to calculate the following quantities

  • Partial van Hove functions

  • Partial intermediate scattering functions

  • Partial dynamic structure factors, including the incoherent (or self) part

  • Longitudinal and transversal partial current correlations

  • Spectral energy densities

The main input consists of a trajectory from a MD simulation, i.e., a file containing snapshots of the particle coordinates, and optionally velocities that correspond to consecutively and equally spaced points in (simulation) time. The following snippet illustrates how one can calculate dynamic structure factors from such a trajectory

traj = Trajectory('', trajectory_format='extxyz')
q_points = generate_spherical_qpoints(traj.cell, q_max=20)
sample = compute_dynamic_structure_factors(traj, q_points=q_points, dt=5, window_size=100)

dynasor has been developed at Chalmers University of Technology in Gothenburg, Sweden, in the Condensed Matter and Materials Theory division at the Department of Physics. Please consult the credits page for information on how to cite dynasor.

For questions and help please use the dynasor discussion forum on dynasor and its development are hosted on gitlab.