Distribution of hydrogen in fcc titanium hydrides: an ab initio study

A.V. Verkhovykh; A.A. Mirzoev

doi:10.48612/letters/2026-4-379-385

Distribution of hydrogen in fcc titanium hydrides: an ab initio study

A.V. Verkhovykh

, A.A. Mirzoev show affiliations and emails

Received 10 June 2026; Accepted 16 August 2026;

Citation: A.V. Verkhovykh, A.A. Mirzoev. Distribution of hydrogen in fcc titanium hydrides: an ab initio study. Lett. Mater., 2026, 16(4) 379-385

BibTex https://doi.org/10.48612/letters/2026-4-379-385

Abstract

Density functional theory calculations demonstrate that hydrogen atoms in FCC titanium preferentially occupy tetrahedral interstitial sites. The most stable configurations are formed when H–H distances are maximized along the body diagonal of the tetrahedral sublattice, resulting in ordered titanium hydrides.

This paper presents a first-principles study of titanium hydrides as promising hydrogen storage materials using density functional theory calculations. The stability of hydrogen in tetrahedral and octahedral interstitial sites was systematically investigated, and the influence of hydrogen concentration and atomic arrangement on the energetics of titanium hydrides was analyzed. The roles of chemical bonding and Coulomb repulsion between hydrogen atoms in determining the energies of different configurations are examined. The effect of the relative arrangement of hydrogen atoms on the energetic stability of hydride phases is analyzed, and the main factors governing the preferential occupation of interstitial sites are identified. Analysis of the calculated configurations reveals stable geometric motifs for hydrogen occupation of tetrahedral interstitial sites that minimize the hydride energy. It is shown that the preferred hydrogen arrangements correspond to the maximum mutual separation of hydrogen atoms along the body diagonal of the cubic lattice formed by tetrahedral sites. The obtained results demonstrate the non-random nature of hydrogen distribution in fcc titanium and establish a link between electronic structure, interatomic interactions, and the formation of ordered hydride phases. The proposed approach provides insight into the atomic-scale mechanisms governing hydrogen ordering and can be used to predict the structural and energetic properties of titanium hydrides across the composition range from TiH to TiH2.

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