An GNU-Octave based script for solving coupled nonlinear equations in the ABO3 perovskite defect thermodynamic models with varying AB ratio to generate Brouwer diagrams of the perovskite oxides as a function of temperature and P(O2) based on the inputs of the defect formation energies and entropies.

The developed models are split into two scenarios (two sets of the Octave codes): 1. B-site cation excesss (A/B 1: The model contains the following defect reactions - oxygen vacancy formation, Schottcky defect formation, charge disproporationation, A_B antisite defect formation (e.g. La_B), and A'_B antisite formation (e.g., Sr_B).