Introduction
============

*Reproducing molecular ESP from partial charges and more...*

This library has been created to aid research in the area of partial charge assignment and molecular electrostatic potential (ESP) fields.

Highlights
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The following is a non-exhaustive list of the capabilities of this library alongside the relevant modules:

* Extracting charges from Gaussian output files (`gaussian_format` module) and ``resp`` input/output files (`respin_charges_format` module).
* Parsing and writing Gaussian "cube" files (`cube_format` module).
  The extracted values and the associated `Mesh` object (collection of points in space) are contained in a `Field` object, an instance of a class central to this library.
* Parsing ESP field information from the file format generated by Gaussian and saving it to a ``resp``-compatible format (`esp_util` module).
  This is a convenient way of obtaining popular fitting meshes, such as MK and CHelpG.
* Reproducing ESP field at points of a mesh from point charges on atoms and calculating e.g. the difference from or RMS error with respect to the another ESP field (`calc_fields` module).
* Creating single-molecule, single-structure input files for the ``resp`` program (`respin_format` module).
  For common types of fitting, such as two-stage RESP or fitting with equivalencing, running the ``resp`` program is conveniently abstracted away (`resp_wrapper` module).
  It is also easy to implement customized variations of the fitting (`respin_generation` module).
* "*A posteriori*" averaging of charges according to provided chemical equivalence relations (`charge_util` module).