pymatgen

combined

Analyzes, validates, converts, and transforms materials structures and computed materials data with pymatgen. Use for local phase diagrams, symmetry sensitivity, electronic-structure I/O, and bounded Materials Project queries. Materials science toolkit. Crystal structures (CIF, POSCAR), phase diagrams, band structure, DOS, Materials Project integration, format conversion, for computational materials science.

When to use

Working with crystal structures or molecular systems in materials science
Converting between structure file formats (CIF, POSCAR, XYZ, etc.)
Analyzing symmetry, space groups, or coordination environments
Extracting Wyckoff letters, multiplicities, and representative fractional coordinates from CIF files (see `references/wyckoff-positions-from-cif.md` — use `get_symmetry_dataset().wyckoffs`, not `get_symmetrized_structure().wyckoff_symbols`)
Computing phase diagrams or assessing thermodynamic stability
Analyzing electronic structure data (band gaps, DOS, band structures)
Generating surfaces, slabs, or studying interfaces
Accessing the Materials Project database programmatically

When not to use

untrusted general object graph loading
pickle usage
implicit oxidation state guessing
silent acceptance of parser fixes

Skill page

Conflict

The K-Dense-AI copy is a distinct, more rigorous procedure (pinned versions, provenance, validation, symmetry tolerance reporting, safe intake, database disclosure) that the other three copies do not contain. The other three copies are near-identical quick-start guides, but the benchflow-ai copy adds a specific Wyckoff-position extraction step that the other two lack. Crowning one copy would hide the K-Dense-AI workflow and the benchflow-ai Wyckoff detail.