If you're doing computational materials science, this is the standard library for crystal structure manipulation and analysis. It handles structure I/O across 100+ formats (CIF, POSCAR, XYZ), symmetry analysis, phase diagram construction, and electronic structure processing from codes like VASP and Quantum ESPRESSO. The Materials Project integration is the standout feature, letting you pull computed materials data directly into your workflows. The learning curve is real since it's a massive library, but the documentation is solid with specific scripts for common tasks like batch format conversion and automated structure analysis. If you're already working with DFT calculations or need to manipulate crystal structures programmatically, you'll use this constantly.
npx skills add https://github.com/k-dense-ai/scientific-agent-skills --skill pymatgen