Supported Geometry Formats

This library supports reading and writing molecular structures in the following formats. All formats can be auto-detected by file extension or explicitly specified using the filetype enumerator.

General ASCII Formats

• xyz format - Simple Cartesian coordinate format (.xyz, .log)
• Connection table files - MDL molfile and SDF formats (.mol, .sdf)
• Protein Data Bank - PDB format for biomolecules (.pdb)

JSON-based Formats

• QCSchema JSON - MolSSI QCSchema format (.qcjson, .json)
• Chemical JSON - Avogadro Chemical JSON (.cjson, .json)
• Pymatgen JSON - Pymatgen Molecule/Structure (.pmgjson, .json)

Program-specific Formats

• Turbomole coord - Turbomole/riper coordinate format (.tmol, .coord)
• VASP POSCAR - VASP geometry input (.vasp, .poscar, .contcar)
• DFTB+ gen format - DFTB+ general format (.gen)
• Gaussian external - Gaussian external program input (.ein)
• FHI-aims geometry.in - FHI-aims input format (geometry.in)
• Q-Chem molecule - Q-Chem molecule block (.qchem)

Format Detection

File formats are detected automatically based on:

1. File extension (e.g., .xyz, .mol, .vasp)
2. Basename (e.g., coord, POSCAR, CONTCAR, geometry.in)

When automatic detection is not possible (e.g., reading from stdin), use the format hint options in mctc-convert or the filetype enumerator in the library API.