The Electronic Crystal Calculation Prep (ECCP) Program

Authors: Dr. Geoffrey Weal^*,†, Dr. Chayanit Wechwithayakhlung^†, Dr. Josh Sutton^*, Dr. Daniel Packwood^†, Dr. Paul Hume^*, Prof. Justin Hodgkiss^*

^* Victoria University of Wellington, Wellington, New Zealand; The MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington, New Zealand.

^† Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Kyoto, Japan.

Group pages: https://people.wgtn.ac.nz/paul.hume/grants, https://www.packwood.icems.kyoto-u.ac.jp/, https://people.wgtn.ac.nz/justin.hodgkiss/grants

What is the Electronic Crystal Calculation Prep (ECCP) Program

The Electronic Crystal Calculation Prep (ECCP) program is designed create the Gaussian/ORCA files needed to perform DFT calculations upon the molecules in molecular crystals. The DFT calculations allow the user to calculate the electronic properties of molecules, such as:

• excited state properties,
• reorganisation energies,
• as well as electronic intermolecular properties, including electronic coupling, and exciton and charge diffusion.

Installation

It is recommended to read the installation page before using the ECCP program. See Installation: Setting Up ECCP and Pre-Requisites Packages for more information. Note that you can install ECCP through pip3 and conda.

Guide To Using ECCP

The ECCP program is one in a series of programs that are designed to be used in the workflow shown below. After you have installed ECCP, see How To Use The ECCP Program to learn about how to use this program.

The Grand Scheme

The ECCP program is used as part of a grand scheme for calculating the excited-state electronic properties of molecules in a crystal. This includes simulations of exciton and charge diffusion through crystal structures, in particular for organic molecules (but not limited to them). This scheme is shown below, along with where the ECCP program is used in this scheme.