Theory Guide
===========

This guide provides the theoretical background for the gauNEGF package.

.. toctree::
   :maxdepth: 2
   :caption: Theory Topics

   introduction
   negf_dft
   transport
   best_practices

Overview
--------

gauNEGF implements Non-Equilibrium Green's Function (NEGF) calculations with Density Functional Theory (DFT) using Gaussian basis sets. The key theoretical components are:

1. **NEGF Formalism**
   
   * Green's functions in quantum transport
   * Self-energy and contact effects
   * Current and transmission calculations

2. **DFT Integration**
   
   * Density matrix construction
   * Self-consistent field iterations
   * Basis set considerations

3. **Transport Theory**
   
   * Landauer-Büttiker formalism
   * Coherent transport
   * Spin-dependent transport

Getting Started
-------------

For a structured approach to understanding the theory:

1. Start with :doc:`introduction` for basic concepts and system setup
2. Dive into :doc:`negf_dft` for detailed methodology
3. Explore :doc:`transport` for transport calculations
4. Review :doc:`best_practices` for optimal usage