Point-Defect Formation Energy (MLIP)

Goal

To calculate the formation energy ($E_f$) of neutral point defects (vacancies, substitutions, and interstitials) using Machine Learning Interatomic Potentials (MLIPs). Formation energy is defined as:

$$E_f = E_\mathrm{defect} - \frac{n_\mathrm{defect}}{n_\mathrm{bulk}} E_\mathrm{bulk} + \sum_i \Delta n_i \mu_i$$

where $E_\mathrm{defect}$ and $E_\mathrm{bulk}$ are the total energies of the defective and pristine supercells, $n$ is the number of atoms, $\Delta n_i$ is the change in number of species $i$, and $\mu_i$ is the chemical potential of species $i$.

Instructions

1. Select Level of Theory

Choose an MLIP model. See ml-foundation-potentials for guidance.

• Recommended: r2SCAN-level potentials for inorganic defects (e.g., MACE-MH-1 with matpes_r2scan head).
• Use the same model for bulk and defect calculations.