.. Phonon_Dynamics documentation master file, created by
   sphinx-quickstart on Thu Jun 28 12:22:07 2018.
   You can adapt this file completely to your liking, but it should at least
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.. _Proposal: https://www.anl.gov/cnm/user-information/call-proposals
.. _Carbon: https://wiki.anl.gov/cnm/HPC/Hardware_Details  

Welcome to Phonon_Dynamics's documentation!
===========================================

This code simulates the time-evolutions of phonons in contact with (non-equilibrium) charge carriers (electrons/holes). This is accomplished by solving the Boltzmann transport equation for the coupled electron-, hole- and phonon-subsystems using a direct time-stepping technique. The code can currently model this dynamics in the presence of mode-dependent 3-phonon phonon-phonon interactions and first-order electron-phonon interactions using Fermi Golden Rule. The code is interfaced with EPW and Quantum Espresso. 

The code is divided into multiple steps:

.. toctree::
   :maxdepth: 4

   Assembling first-principles inputs <Assembling inputs>
   Finding scattering phase spaces <Finding phase spaces>
   Computing phonon-phonon matrix elements
   Running phonon dynamics


Running the code is achieved through running the bash file **Phonon_Dynamics_1.sh** and **Phonon_Dynamics_2.sh**. The code can run dynamics for holes, electrons, or both.


The code offers these other functionalities as well

| * Graphing the compound's bandstructure
| * Graphing the temperature decay of electrons and holes as well as the thermalization of phonons
| * Graphing phonon thermalization as a function of modes


Files Name and Role
===================

omegaq.freq: Phonon frequencies (in cm-1) read by the find_scattering_events code (no negative/imaginary frequency can be present in this file) 
phband.freq: Phonon frequencies (in meV) for plotting/analysis purpose

Running the Code
================

Upon approval and activation of a CNM user Proposal_ , the code can be found in the shared directory `/home/share/cnmProposalNumber/`. 
The code can be run on Carbon_ using the PBS scheduling system. An example script for running on Carbon:


    .. code-block:: bash

       #!/bin/bash
       #PBS -l nodes=1:ppn=16:gen4
       #PBS -l walltime=50:00:00
       #PBS -N ...
       #PBS -A cnm50326
       cd $PBS_O_WORKDIR
       export OMP_NUM_THREADS=16
       module load gcc/4.9/4.9.3-1
       g++ -fopenmp ph_dynamics2.cpp
       ./a.out > filout

Running the same code on Argonne LCRC:

    .. code-block:: bash

       #!/bin/bash
       #SBATCH -N 1
       #SBATCH --ntasks-per-node=36
       #SBATCH --job-name=sil_dynamics_vb
       #SBATCH --time=12:00:00
       #SBATCH -A ...
       #SBATCH -p bdwall
       export OMP_NUM_THREADS=36
       g++ -fopenmp ph_dynamics2.cpp
       ./a.out > filout