Ab initio study of H, B, C, N, O, and self-interstitial atoms in hcp-Zr

In this work, we investigate the stabilities of H, B, C, N, O, and Zr atoms at various interstitial sites in hcp-Zr using a first-principles theoretical approach. The formation energy of each interstitial atom at each site in the hcp crystal was determined, and the difference in the energy at different sites were considered as a static energy barrier to predict energetically favored diffusion pathways. Linear and non-linear prediction models for the interstitial formation energy were developed using readily accessible chemical and structural input parameters. We show that a simple linear model predicts the formation energies of the interstitial atoms with an R² of 97%.