MixPI: Mixed-time slicing path integral software for quantized molecular dynamics simulations

Area of Science:

• Computational Chemistry
• Physical Chemistry
• Materials Science

Background:

• Nuclear quantum effects (NQEs) significantly influence condensed phase systems.
• Existing path integral molecular dynamics (PIMD) software lacks flexibility for mixed quantum-classical approaches.
• Simulating systems with localized quantum phenomena requires specialized computational tools.

Purpose of the Study:

• Introduce MixPI, a novel software for implementing mixed quantum-classical path integral simulations.
• Enable the study of condensed phase systems where only a subset of degrees of freedom (dofs) exhibit significant NQEs.
• Provide a tool for investigating electron and proton transfer, and NQEs in biological and material systems.

Main Methods:

• Developed MixPI software for mixed quantum-classical path integral molecular dynamics (PIMD) simulations.
• Implemented simulations on a water model to compute average energy and radial distribution functions.
• Applied MixPI to a solvated metal cation (M2+) with a quantized electron on an M3+ ion.

Main Results:

• Benchmarked MixPI's effectiveness in computing average energy and radial distribution functions for a water model.
• Demonstrated MixPI's capability to systematically investigate the origins of NQEs.
• Successfully computed radial distribution functions for a complex solvated metal cation system using MixPI.

Conclusions:

• MixPI software effectively implements mixed quantum-classical PIMD simulations for systems with important NQEs.
• The software is particularly useful for studying electron/proton transfer and localized NQEs in condensed phase, biological, and material systems.
• MixPI provides a powerful and flexible platform for advancing simulations of quantum phenomena in complex environments.