..
    : PyBEST: Pythonic Black-box Electronic Structure Tool
    : Copyright (C) 2016-- The PyBEST Development Team
    :
    : This file is part of PyBEST.
    :
    : PyBEST is free software; you can redistribute it and/or
    : modify it under the terms of the GNU General Public License
    : as published by the Free Software Foundation; either version 3
    : of the License, or (at your option) any later version.
    :
    : PyBEST is distributed in the hope that it will be useful,
    : but WITHOUT ANY WARRANTY; without even the implied warranty of
    : MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    : GNU General Public License for more details.
    :
    : You should have received a copy of the GNU General Public License
    : along with this program; if not, see <http://www.gnu.org/licenses/>
    :
    : --

.. _user_iodata_intro:

Preliminaries
#############

The :py:class:`~pybest.io.iodata.IOData` container is a class that handles all
I/O operations in PyBEST. It allows the user to conveniently read/dump
data from/to disk using various file formats. Furthermore, the
:py:class:`~pybest.io.iodata.IOData` container is used to generate internal
checkpoint files that can be used for restarts in PyBEST.
In this section, we will briefly explain how to properly use the
:py:class:`~pybest.io.iodata.IOData` container and mention the most important
PyBEST standards and conventions concerning I/O operations and the
:py:class:`~pybest.io.iodata.IOData` container.

Since all electronic structure methods return an instane of the
:py:class:`~pybest.io.iodata.IOData` class, the corresponding data (that is,
the results of an electronic structure calculation) can be easily accessed,
modified, and manipulated. See, for instance,
:ref:`user_iodata_dumping` and :ref:`user_iodata_reading` for more details.
Specifically, :ref:`user_iodata_dumping_filling` will show you how to create
new attributes and how to delete existing attributes in the
:py:class:`~pybest.io.iodata.IOData` container.

.. note::

    Using a simple syntax described :ref:`here <user_iodata_dumping_filling>`,
    you can easily

        - create new attributes
        - modify existing attributes
        - delete existing attributes

    in the :py:class:`~pybest.io.iodata.IOData` container.