httk.io.vasp.poscar_reader
==========================

.. py:module:: httk.io.vasp.poscar_reader

.. autoapi-nested-parse::

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

   :func:`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
---------

.. autoapisummary::

   httk.io.vasp.poscar_reader.read_poscar


Module Contents
---------------

.. py:function:: 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 :class:`os.PathLike`, opened through
   :class:`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
   :class:`ValueError` naming the offending line.