Theoretical prediction of novel Li–Ag(II)–F quantum magnets using evolutionary algorithms

Abstract

This work explores the thermodynamic stability, crystal structures and magnetic properties of ternary Li–Ag(II)–F compounds. Convex-hull analysis shows all predicted structures slightly above the LiF + AgF₂ decomposition line, indicating their metastability. Nevertheless, synthetic routes employing F₂ gas or F radicals, or a thermal decomposition of LiAgF₄ precursor, should allow for their preparation. All structures exhibit antiferromagnetic ground states, with LiAgF₃_2 polymorph exhibiting an exceptionally large superexchange constant of ca. –380 meV within [Ag₂F₇] dimers.