mat-md-probability-density

Generate CHGCAR probability density maps from MD trajectory fractional coordinates.

144|21|Updated Jan 8, 2026
One-click install
npx skills add https://github.com/learningmatter-mit/AtomisticSkills --skill mat-md-probability-density
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: mat-md-probability-density
Source: https://github.com/learningmatter-mit/AtomisticSkills/tree/main/.agents/skills/mat-md-probability-density
Command: npx skills add https://github.com/learningmatter-mit/AtomisticSkills --skill mat-md-probability-density

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill requires ase, numpy, pymatgen, scipy, and includes scripts (resource) components.

What problem does it solve?

It calculates and visualizes the spatial probability density of mobile ions from a molecular dynamics trajectory so you can identify likely conduction pathways and preferred ion sites in a crystal.

Core Features & Use Cases

  • Probability density from MD trajectories: Converts time-sampled fractional coordinates of a chosen species into a volumetric grid suitable for CHGCAR output.
  • Smoothing and optional log compression: Applies Gaussian smoothing to make sparse hopping visually coherent, and supports logarithmic compression to better reveal continuous diffusion paths from short trajectories.
  • VESTA-ready visualization: Produces CHGCAR data that can be opened directly in VESTA for isosurface-based pathway visualization.

Quick Start

Run the probability-density calculation for your MD trajectory using the base-agent environment to generate a CHGCAR that you can open in VESTA.

Frequently Asked Questions about mat-md-probability-density

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I map ionic diffusion pathways from an ASE MD trajectory?

You can map ionic diffusion pathways by converting time-sampled fractional coordinates of mobile ions from an ASE .traj file into a volumetric probability density grid. This grid is output as a CHGCAR file for direct isosurface visualization in VESTA.

How can I visualize solid-state electrolyte conduction pathways in VESTA?

To visualize conduction pathways in VESTA, generate a CHGCAR-format probability density map from your MD trajectory. The Skill aggregates fractional coordinates of diffusing ions into a structured grid that VESTA reads natively for isosurface rendering.

Can I smooth sparse ionic hopping data from short AIMD trajectories?

Yes, you can smooth sparse ionic hopping data from short AIMD trajectories using built-in Gaussian smoothing. The tool also supports logarithmic compression to better reveal continuous diffusion paths that might otherwise appear disjointed.

How do I skip equilibration frames when calculating probability density?

You can skip equilibration frames by setting the ignore_ps parameter in the execution script. This excludes initial trajectory data before the system stabilizes, ensuring the probability density calculation only includes equilibrated ionic diffusion.

What file formats and libraries are required to generate a CHGCAR probability density map?

Generating a CHGCAR probability density map requires an ASE .traj trajectory file as input and uses numpy, scipy, and pymatgen libraries for grid computation. The output is a standard CHGCAR volumetric file for visualization.

How do I select specific diffusing ion species for trajectory analysis?

You select specific diffusing ion species through species selection parameters in the provided script. This filters the MD trajectory fractional coordinates so the probability density grid only aggregates positions of the targeted mobile ions.