general-property-units

Define ASE-standard energy, force, and stress units across MLIP and DFT toolchains.

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

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

This Skill resolves confusion and errors caused by inconsistent units for energy, forces, and stress when mixing MLIP predictions, DFT outputs, and simulation tooling.

Core Features & Use Cases

  • Authoritative ASE-standard conventions: Defines the project’s standard units for energy, forces, and stress (including Voigt ordering) to prevent silent mismatches.
  • MLIP and trainer-specific conversion rules: Documents how inference and training labels map across MACE, CHGNet, UMA, and MatGL, including the special MatGL stress conversion path.
  • DFT output normalization (e.g., VASP): Covers unit and sign conventions for VASP stress so downstream comparisons are physically consistent.
  • Conversion factor quick reference: Provides commonly needed conversion constants and reminders for safe reporting (e.g., MAE units).

Quick Start

Use the general-property-units Skill to verify that any energy, force, or stress values you exchange between ASE, MLIP wrappers, training datasets, and VASP/DFT outputs are expressed in the correct units and with the correct sign conventions.

Frequently Asked Questions about general-property-units

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

FAQPage Schema
How do I convert VASP stress to GPa for ASE comparisons?

To convert VASP stress for ASE comparisons, you must apply the kB to eV/ų conversion and account for the VASP stress sign inversion to ensure physical consistency. This Skill enforces those required conversions for downstream reporting.

What are the standard ASE units for energy, forces, and stress?

The standard ASE units for energy, forces, and stress define a single source of truth using eV for energy, eV/Å for forces, and specific Voigt ordering for stress. This Skill establishes these conventions to prevent silent mismatches across toolchains.

Does MatGL require specific unit conversions for stress predictions?

Yes, MatGL requires a special stress conversion path from eV/ų to GPa. This Skill documents the trainer-specific conversion rules for MatGL alongside MACE, CHGNet, and UMA to maintain consistent MLIP inference and training labels.

Why do my MLIP and DFT stress values have mismatched signs?

Mismatched stress signs often result from VASP stress sign inversion conventions conflicting with MLIP wrappers. This Skill resolves these inconsistencies by documenting DFT output normalization and enforcing ASE-standard sign conventions across all toolchains.

Can I use this to normalize training labels for MACE and CHGNet?

Yes, you can use this Skill to normalize training labels for MACE and CHGNet. It maps how training labels and inference outputs convert across multiple MLIP frameworks, ensuring all energy, force, and stress data adheres to authoritative ASE-standard units.