httk.io.vasp.poscar_reader

A string-preserving reader for VASP POSCAR/CONTCAR files.

read_poscar() parses a POSCAR/CONTCAR file into a neutral, JSON-able mapping whose numeric fields are kept as the verbatim strings found in the file. It performs no numeric conversion and imports nothing from httk-atomistic; turning the mapping into a Structure is the job of httk.atomistic.structure_from_poscar.

Functions

read_poscar(→ dict[str, Any])

Parse a VASP POSCAR/CONTCAR into a neutral, string-preserving mapping.

Module Contents

httk.io.vasp.poscar_reader.read_poscar(source: Any) → dict[str, Any]

Parse a VASP POSCAR/CONTCAR into a neutral, string-preserving mapping.

source may be a filename (str or os.PathLike, opened through httk.core.TextstreamFileView so compressed files such as CONTCAR.bz2 are decompressed transparently) or an already-open text stream / iterable of lines.

The returned mapping has the keys format (always "vasp-poscar"), comment, scale and volume (exactly one is a string, the other None), cell (a 3x3 list of coordinate strings), symbols (list[str] for VASP-5, None for VASP-4), counts (list[int]), cartesian (bool), coords (an N``x3 list of strings), and ``selective_dynamics (an N``x3 list of booleans when the file declares selective dynamics, else ``None). Malformed input raises a clear ValueError naming the offending line.