DL_POLY Quantum Suite

Stet-of-the-Art Path Integral Molecular Dynamics Simulations

Software

DL_POLY quantum 2.0

DL_POLY quantum 2.0, a vastly expanded software based on DL_POLY Quantum 1.0, is a highly parallelized computational suite written in FORTRAN77 with a modular structure for incorporating nuclear quantum effects into large-scale/long-time molecular dynamics simulations. This is achieved by presenting users with a wide selection of state-of-the-art dynamics methods that utilize the isomorphism between a classical ring polymer and Feynman’s path integral formalism of quantum mechanics. The flexible and user-friendly input/output handling system allows the control of methodology, integration schemes, and thermostatting. DL_POLY Quantum is equipped with a module specifically assigned for calculating correlation functions and printing out the values for sought-after quantities, such as dipole moments and center-of-mass velocities, with packaged tools for calculating infrared absorption spectra and diffusion coefficients. A detailed description of the DL_POLY Quantum 2.0 is available in our Software paper at the J. Chem. Phys. while the open-source software package can be accessed via Github repository. A brief summary of the capabilities of the software is provided below. 

  • Path Integral Molecular Dynamics (PIMD) simulations in normal mode coordinates as well as staging coordinates.
  • Path integral Langevin equation (PILE) thermostat for PIMD simulations.
  • Path integral generalized Langevin equation thermostat (PIGLET).
  • Ring Polymer Molecular Dynamics (RPMD) simulations.
  • Thermostatted RPMD simulations.
  • Partially Adiabatic Centroid Molecular Dynamics (PA-CMD) simulations.

DL_POLY quantum 1.0

DL_POLY quantum 1.0 is an extensively modified code based on the open-source DL_POLY classic v1.10 for large-scale long-time molecular dynamics simulations in condensed phases. This code is available to public through our GitHub repository.

Some of most significant modifications in DL_POLY quantum v1.0 are as following:

  • Nose-Hoover Chain (NHC) thermostat for classical simulations in canonical ensemble based on Suzuki-Yoshida scheme. 
  • Nose-Hoover Chain thermostat/barostat for isothermal-isobaric ensemble through Martyna-Tobias-Klein (MTK) algorithm for classical MD simulations.
  • The four-site flexible quantum water potential model qTIP4P/f.
  • A 12-6 Lennard-Jones external potential for confinement simulations.

Note: The DL_POLY quantum project is ongoing with new implementations underway; a manual will be available in near future. For suggestions, feedbacks and questions please contact Dr. Farnaz Shakib at shakib@njit.edu.