Self-consistent finite-size corrections for structural relaxations

Develop a self-consistent finite-size correction methodology that can be applied during structural relaxations in Kohn–Sham density functional theory calculations of polarons, yielding finite-size–corrected wave functions and forces so that geometry optimization accounts for interactions with periodic images and ionic polarization rather than relying on a posteriori corrections.

Background

Finite-size effects in supercell calculations of polarons arise from Coulomb interactions with periodic images and neutralizing backgrounds, affecting both charged and neutral states due to ionic polarization. Throughout the paper the authors explain that current practice applies finite-size corrections a posteriori to energies and levels, which leaves forces and structures uncorrected and can bias polaronic distortions. They suggest that a self-consistent correction implemented directly in the Kohn–Sham equations would produce corrected wave functions and forces and reduce discrepancies among charged and neutral formulations (γDFT, μDFT, pSIC).

They note prior work by da Silva et al. that introduced a self-consistent correction at the level of total energy, but this has not yet been extended to structural relaxations. The authors explicitly identify this extension as future work needed to improve the reliability of polaron geometry optimization under finite-size effects.