Overview

Workflow used to determine the symmetry degeneracy of alloy supercells with substitutions amongst transition metal sites. This information is used for computing configurational entropy. The project here is a specific case for the Co_xMn_{3-x}O_4 alloy with substitutions amongst Co and Mn sites which occupy octahedral (oh) and tetrahedral (td) crystallographic sites. Two datasets are processed, one where td sites are preferentially filled first (set A) and one where oh sites are preferentially filled first (set B).

Dependencies

• Python3
• ase
• spglib

Getting started

Modify INPUTS section in process_dataList.py and run with python process_dataList.py.

The code runs in parallel. During execution, the user will be shown how many processors are available to them to use and asked how many the program should use. It is advisable not to use too many of those you have available or your machine will become sluggish!

Inputs:

• File containing list of directories where unrelaxed POSCAR's can be found (note here they are called 'POSCAR_orig')
• File containing data from previous step of workflow (to be appended by this step)
• Settings such as threshold (tolerance spglib will use for assigning space groups) and scaling which is used to determine number of random configurations to attempt when searching for equivalent structures (total attempts is total_combination_space*scaling to increase likelihood of sampling most of the possible substitutions). The final count of symmetrically degenerate structures for each input structure is divided by scaling.