Theoretical exploration of high-pressure crystal structures and valence states in the Li-Cl system

Chlorine plays an important role in the production of drinking water, disinfectants and textiles, but its valence states are seldom studied. Anionic chlorine of - 1 valence (Cl-) is the only negative valence state reported to date. This study considered stable structures and electronic properties of Li-Cl systems at pressures of 0-100 GPa. Among the predicted stable stoichiometries, Li2Cl, Li3Cl, Li4Cl, Li5Cl are electrides. Under extreme pressures, the calculated Bader charge of Cl indicates an unconventional negative valence state of - 2. Our results provide theoretical support for the further study of Li-Cl compounds and expansion of the valence states of Cl. (c) 2022 Published by Elsevier B.V.