mat-phase-diagram

mat-phase-diagram is a skill for Claude Code, Codex from learningmatter-mit/AtomisticSkills. It costs 22 tokens per session (1,115 once invoked), scanned A, original, MIT.

A tool for retrieving and plotting precomputed phase diagrams from Materials Project, an online database of calculated materials properties. These diagrams show stable compounds, competing phases, and how far a material is from the stability boundary.

In plain words
What is it for?
Use it to inspect chemical systems, compare stable and unstable compounds, and visualize convex-hull relationships.
Why use it?
It helps assess whether a compound is thermodynamically stable and which other phases may form instead.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/learningmatter-mit/atomisticskills/mat-phase-diagram
Any agent
npx skills add learningmatter-mit/AtomisticSkills --skill mat-phase-diagram
Clone the repo
git clone --depth 1 https://github.com/learningmatter-mit/AtomisticSkills

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for mat-phase-diagram

README.md
[![agentmods](https://agentmods.dev/badge/skills/learningmatter-mit/atomisticskills/mat-phase-diagram.svg)](https://agentmods.dev/skills/learningmatter-mit/atomisticskills/mat-phase-diagram)
Your own site
<a href="https://agentmods.dev/skills/learningmatter-mit/atomisticskills/mat-phase-diagram"><img src="https://agentmods.dev/badge/skills/learningmatter-mit/atomisticskills/mat-phase-diagram.svg" alt="Measured on agentmods" height="20"></a>
Per session 22 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,115 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00022 $0.01115
Opus 5 $0.00011 $0.00558
Sonnet 5 $0.00004 $0.00223
Haiku 4.5 $0.00002 $0.00112

Measured yesterday against content hash eff87f3af766, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

mat-phase-diagram scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

The scan reads SKILL.md. This mod also ships 2 executable files (examples/Li-O/li_o_example.sh, scripts/get_phase_diagram.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.agents/skills/mat-phase-diagram/SKILL.md · 140 lines

How it starts

The opening of the file, as written. The whole thing — 140 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Phase Diagram Retrieval

Goal

Retrieve pre-computed phase diagrams from Materials Project to analyze thermodynamic stability, competing phases, and convex hull relationships. Phase diagrams are essential for understanding:

  • Which compounds are stable at 0 K
  • Energy above hull (formation energy distance to the convex hull)
  • Competing phases that may form during synthesis
  • Thermodynamic driving forces for phase transformations

Instructions

1. Basic Phase Diagram Retrieval

Retrieve a phase diagram for a chemical system:

# Env: base-agent
python .agents/skills/mat-phase-diagram/scripts/get_phase_diagram.py \
  --chemsys "Li-O" \
  --output li_o_phase_diagram.json

Output: JSON file containing the phase diagram data (entries, energies, hull)

2. Generate Phase Diagram Plot

Add --plot flag to create a visualization:

# Env: base-agent
python .agents/skills/mat-phase-diagram/scripts/get_phase_diagram.py \
  --chemsys "Li-O" \
  --output li_o_pd.json \
  --plot li_o_pd.png

Output: PNG plot showing the convex hull and stable/unstable phases

3. Use Different DFT Functional

By default, retrieves GGA+U phase diagrams. For R2SCAN data:

# Env: base-agent
python .agents/skills/mat-phase-diagram/scripts/get_phase_diagram.py \
  --chemsys "Li-Fe-P-O" \
  --thermo_type "R2SCAN" \
  --output lifepo4_r2scan_pd.json \
  --plot lifepo4_r2scan_pd.png

Thermo types:

  • GGA_GGA+U (default): Standard PBE with U corrections
  • R2SCAN: Meta-GGA functional (more accurate)
  • GGA: Pure PBE without U corrections

Integration with Other Skills

With material-stability Skill

Use phase diagrams to visualize competing phases:

# 1. Get phase diagram
python .agents/skills/mat-phase-diagram/scripts/get_phase_diagram.py \
  --chemsys "Li-O" \
  --output li_o_pd.json \
  --plot li_o_pd.png

# 2. Check specific material's position on hull
python .agents/skills/mat-db-mp/scripts/query_mp.py \
  --formula "Li2O" \
  --properties energy_above_hull formation_energy_per_atom \
  --output li2o_stability.json

Read the full file on GitHub · 140 lines

Files

What ships with it

6 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday First seen · 140 lines · 22 tokens per session scan A eff87f3af766

Subscribe to this mod's changes

mat-phase-diagram is a skill published in the GitHub repository learningmatter-mit/AtomisticSkills (160 stars, last pushed yesterday), licensed MIT. It adds 22 tokens to every session and 1,115 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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