Install the "mat-defect-energy" agent skill from https://github.com/learningmatter-mit/AtomisticSkills/tree/main/skills/mat-defect-energy into .claude/skills/mat-defect-energy/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "mat-defect-energy", then confirm the skill loads.
Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Type this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
skills CLI
$ npx skills add learningmatter-mit/AtomisticSkills --skill mat-defect-energy -a codex
Project install goes to .agents/skills/; add -g for ~/.codex/skills/.
Install the "mat-defect-energy" agent skill from https://github.com/learningmatter-mit/AtomisticSkills/tree/main/skills/mat-defect-energy into .agents/skills/mat-defect-energy/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "mat-defect-energy", then confirm the skill loads.
Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
skills CLI
$ npx skills add learningmatter-mit/AtomisticSkills --skill mat-defect-energy -a cursor
Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.
Install the "mat-defect-energy" agent skill from https://github.com/learningmatter-mit/AtomisticSkills/tree/main/skills/mat-defect-energy into .cursor/skills/mat-defect-energy/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "mat-defect-energy", then confirm the skill loads.
Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
skills CLI
$ npx skills add learningmatter-mit/AtomisticSkills --skill mat-defect-energy -a gemini-cli
Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.
Install the "mat-defect-energy" agent skill from https://github.com/learningmatter-mit/AtomisticSkills/tree/main/skills/mat-defect-energy into .gemini/skills/mat-defect-energy/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "mat-defect-energy", then confirm the skill loads.
Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Installs for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
skills CLI
$ npx skills add learningmatter-mit/AtomisticSkills --skill mat-defect-energy -a github-copilot
Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.
Install the "mat-defect-energy" agent skill from https://github.com/learningmatter-mit/AtomisticSkills/tree/main/skills/mat-defect-energy into .github/skills/mat-defect-energy/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "mat-defect-energy", then confirm the skill loads.
GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
skills CLI
$ npx skills add learningmatter-mit/AtomisticSkills --skill mat-defect-energy -a opencode
OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
Install the "mat-defect-energy" agent skill from https://github.com/learningmatter-mit/AtomisticSkills/tree/main/skills/mat-defect-energy into .opencode/skills/mat-defect-energy/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "mat-defect-energy", then confirm the skill loads.
OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
Skill name
mat-defect-energy
GitHub stars
175
Token cost
~1.7k tokens
SKILL.md length
555 words
Files
8 (incl. scripts)
Skills in repo
129
Repo updated
First seen
Licence
MIT
At a glance
Calculate point-defect formation energies (vacancies, substitutions, interstitials) using MLIPs.
Works in 6 steps: Select Level of Theory → Obtain Bulk Structure → Relax Bulk Structure → …
SKILL.md covers Goal, Instructions, Examples and Constraints
Runs Python scripts from its folder
What it does
Mat Defect Energy is an agent skill from learningmatter-mit/AtomisticSkills. Calculate point-defect formation energies (vacancies, substitutions, interstitials) using MLIPs.
Its SKILL.md is about 1.7k tokens, which your agent loads only when the skill is triggered. The skill folder holds 10 other files, including scripts (for example `examples/MgO_vacancy/README.md`, `examples/MgO_vacancy/defect_energies.json` and `scripts/calculate_defect_energy.py`).
It works with Model Context Protocol. The repository describes itself as: Integrating AtomisticSkills into Agentic IDEs (Cursor, Claude Code, Codex, Google Antigravity, Hermes Agent, etc). The licence is MIT.
Example prompts
“/mat-defect-energy”
Requirements
Python 3
Workflow steps
6 steps, taken from the step headings in SKILL.md.
Read from SKILL.md and the folder at commit 7f2d86d. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
Ships 2 files in scripts/ (Python), which the agent can run.
From the folder's file list and the shell code blocks in SKILL.md.
Network
Links to these hosts (documentation or services it may open):
github.com
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Mat Defect Energy loads about 1.7k tokens when it runs. Until then it costs about 29 tokens; SKILL.md has 555 words of instructions outside code blocks.
Always· name and description, kept in context so the agent knows when to use it
~29
When it runs· the whole SKILL.md, loaded when a task matches
~1.7k
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); the scripts in this folder are not scanned.
Download SKILL.mdSave it as .claude/skills/mat-defect-energy/SKILL.md (or your agent's skills folder). This skill also uses 7 other files; get the full folder from GitHub.
name
mat-defect-energy
description
Calculate point-defect formation energies (vacancies, substitutions, interstitials) using MLIPs.
metadata.category
materials
metadata.venv
cpu, mlip
Point-Defect Formation Energy (MLIP)
<!-- mcp-tools-note -->
[!NOTE]
Steps written server.tool are MCP tool calls: base.search_materials_project_by_formula is the search_materials_project_by_formula
tool of the base server (mcp__base__search_materials_project_by_formula, or
mcp__plugin_atomistic-skills_base__search_materials_project_by_formula when installed as a plugin).
Without a connected server, run the same tools from the shell. Tools named in
one command share a process, so a model loaded by load_model stays loaded:
bash
${CLAUDE_SKILL_DIR}/../../venv/run cpu python -m src.mcp_server.cli base search_materials_project_by_formula key=value
${CLAUDE_SKILL_DIR}/../../venv/run mlip python -m src.mcp_server.cli mace load_model key=value relax_structure key=value
Goal
To calculate the formation energy ($E_f$) of neutral point defects (vacancies, substitutions, and interstitials) using Machine Learning Interatomic Potentials (MLIPs). Formation energy is defined as:
where $E_\mathrm{defect}$ and $E_\mathrm{bulk}$ are the total energies of the defective and pristine supercells, $n$ is the number of atoms, $\Delta n_i$ is the change in number of species $i$, and $\mu_i$ is the chemical potential of species $i$.
substitution — replaces atoms with --substitute_element at each unique site
interstitial — inserts --interstitial_element at Voronoi interstitial sites
all — generates all vacancy types
5. Relax Defect Supercells
Relax without cell relaxation (fixed supercell volume). This applies to the defect
supercells only -- the bulk cell in step 3 and the elemental references in step 6 are
both relaxed with relax_cell=True:
Determines removed/added species and computes $\Delta n_i$
Uses elemental energies from mat-elemental-energies as default chemical potentials (metal-rich limit)
Reports formation energies in eV
If you derive $\mu_i$ yourself instead of reading the library, relax the elemental
reference cell and coordinates (relax_cell=True) with the same potential. A
chemical potential is only meaningful at the reference phase's own minimum for that
potential: evaluating an MP structure at its DFT geometry leaves it above the
potential's minimum and that error passes straight into every formation energy.
For O with TensorNet-PES-MatPES-PBE-2025.2, positions-only relaxation of mp-12957
gives -4.968 eV/atom versus -5.118 fully relaxed -- a 0.15 eV/atom error.
Expected: O vacancy formation energy ~6–8 eV (DFT reference: ~7.2 eV for neutral O vacancy in MgO).
Constraints
Neutral defects only: This skill does NOT handle charged defects. For charged defects with finite-size corrections, use mat-defect-energy-dft.
Fixed cell: Do NOT relax the unit cell during defect relaxation — the supercell must remain fixed to be commensurate with the bulk reference. This constraint is scoped to the defect supercell: the bulk cell and the elemental chemical-potential references are both fully relaxed (cell and coordinates).
Supercell size: Use at least 3×3×3 for cubic systems to minimize periodic image interactions. Formation energies converge with supercell size.
Chemical potential: Default uses metal-rich limit (elemental energies). For environment-specific stability, manually provide chemical potentials.
Environments: Defect generation and energy calculation scripts require cpu.
Mat Defect Energy next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
Mat Defect Energy compared with similar skills
Skill
Stars
Used in
Tokens
Auto-check
Licence
Repo updated
Mat Defect Energy this skilllearningmatter-mit/AtomisticSkills
Walks through building MCP servers in Python or TypeScript that expose tools, resources and prompts to Claude, with templates, registration and testing.
Explains how to bundle Model Context Protocol servers in a Claude Code plugin, covering config files, stdio, SSE, HTTP and WebSocket server types, and authentication.
Required groundwork before any use_figma call: the rules and reference files for running JavaScript in a Figma file through the Plugin API without common failures.
Define a docking search box (center coordinates + box dimensions in Angstroms) from a co-crystal ligand, binding-site residues, or a saved JSON specification.
Calculate point-defect formation energies (vacancies, substitutions, interstitials) using MLIPs. Mat Defect Energy is an agent skill from learningmatter-mit/AtomisticSkills. Calculate point-defect formation energies (vacancies, substitutions, interstitials) using MLIPs.
How do I install Mat Defect Energy in Claude Code?
Run `npx skills add learningmatter-mit/AtomisticSkills --skill mat-defect-energy -a claude-code`. Or copy the skill folder (skills/mat-defect-energy in learningmatter-mit/AtomisticSkills) into .claude/skills/mat-defect-energy in your project. Claude Code loads it when a task matches its description.
How do I install Mat Defect Energy in Codex?
Run `npx skills add learningmatter-mit/AtomisticSkills --skill mat-defect-energy -a codex`. Or copy the skill folder (skills/mat-defect-energy in learningmatter-mit/AtomisticSkills) into .agents/skills/mat-defect-energy in your project. Codex loads it when a task matches its description.
Can I use Mat Defect Energy in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add learningmatter-mit/AtomisticSkills --skill mat-defect-energy -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/mat-defect-energy, .gemini/skills/mat-defect-energy, .github/skills/mat-defect-energy and .opencode/skills/mat-defect-energy in your project.
What does Mat Defect Energy need to run?
Going by SKILL.md and its folder, Mat Defect Energy needs Python for the scripts in its folder. Our summary lists: Python 3.
Does Mat Defect Energy access the network?
SKILL.md names 1 domain. As links in the text: github.com. This is read from the text; nothing was executed.
Is Mat Defect Energy safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. The check reads SKILL.md only: the scripts in the folder are not scanned, so read them before running anything.
What licence does Mat Defect Energy use?
Mat Defect Energy is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Mat Defect Energy use?
About 1.7k tokens (SKILL.md is roughly 6.7k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
What are the alternatives to Mat Defect Energy?
Skills that share tags, products or a category with Mat Defect Energy: MCP Server Builder (anthropics/skills, 180k stars), MCP Server Builder (shareAI-lab/learn-claude-code, 78k stars), MCP Integration for Plugins (anthropics/claude-plugins-official, 37k stars) and Figma use_figma Plugin API Rules (warpdotdev/warp, 65k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Mat Defect Energy?
learningmatter-mit (a GitHub organization) maintains it in learningmatter-mit/AtomisticSkills, which has 175 GitHub stars. The repository holds 129 skills in this directory. The repository was last updated on October 6, 2026.