Ab initio study on the stability and elasticity of brucite

Brucite, or magnesium hydroxide (Mg(OH)₂), is a mineral of great interest owing to its various applications and roles in geological and environmental processes. Its structure, behavior under different conditions, and unique properties have been the subject of numerous studies. As a stable hydrous phase in subduction zones, its elastic anisotropy can significantly contribute to the seismic properties of these regions. Since the brucite structure was first refined in 1967 as having a space group of P-3m1, several possible structures with different symmetries have been proposed. Here, we use ab initio techniques to address different brucite structures' static and dynamic stability. Furthermore, we compute the brucite’s elastic properties and address some consequences for seismic observations.