How Thermodynamically Accessible are Quaternary Mixed-Metal Chalcohalides?

Pascal Henkel; G. Krishnamurthy Grandhi; Jarno Laakso; David Rovira Ferrer; Edgardo Saucedo; Jingrui Li; Paola Vivo; Miguel A. L. Marques; Patrick Rinke

arXiv · 2609.38125

How Thermodynamically Accessible are Quaternary Mixed-Metal Chalcohalides?

Pascal Henkel·G. Krishnamurthy Grandhi·Jarno Laakso·David Rovira Ferrer·Edgardo Saucedo·Jingrui Li·Paola Vivo·Miguel A. L. Marques·Patrick Rinke

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Abstract

Quaternary mixed-metal chalcohalides (MMCHs) are a promising mixed-anion semiconductor family, but their thermodynamic accessibility remains largely unexplored. We combine density functional theory with the Alexandria Materials Database to carry out a rapid and reliable evaluation of the thermodynamic accessibility of 54 M(II)$_2$M(III)Ch$_2$X$_3$ compounds. All evaluated MMCHs are predicted to be thermodynamically unstable, but a considerable fraction of MMCHs lie within computational uncertainty of the convex hull. Their predicted decomposition follows five distinct reaction pathways, most commonly into M(III)$_2$Ch$_3$, M(II)X$_2$, and M(II)Ch. Solution processing of six Sn-based MMCHs supports our analysis. Notably, this includes the first synthesis of the previously unreported Sn$_2$InS$_2$Br$_3$ in a multiphase film. Our approach identifies convex hull proximity and competing phase formation as key constraints on MMCH synthetic accessibility during solution processing, thereby guiding future MMCH exploration.

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Pascal Henkel, G. Krishnamurthy Grandhi, Jarno Laakso, David Rovira Ferrer, Edgardo Saucedo, Jingrui Li, Paola Vivo, Miguel A. L. Marques, Patrick Rinke. 2026-09-29. How Thermodynamically Accessible are Quaternary Mixed-Metal Chalcohalides?. https://arxiv.org/abs/2609.38125

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