The Experimental and Computational Geochemistry Group, previously known as the Geochemistry of Surface Alterations Group, was created as part of the first call for research initiatives of the Andalusian Research Plan, made up chiefly of researchers from CSIC. The main objective is to study the processes responsible for the formation and alteration of minerals on surface conditions, with particular interest in estimating the time required for this to occur. The group investigates processes of soil mineral formation and destruction, the genesis of clay minerals in volcanic or hydrothermal environments, and the transformations of phyllosilicates in conditions of diagenesis. The group was a pioneer in the application of the geochemistry of light stable isotopes (¹³C/¹²C, ¹⁸O/¹⁶O, D/H), which are excellent natural tracers of the geochemical processes governing the Earth system. Specifically, the group carries out isotopic studies of clayey materials, carbonates and waters with the aim of determining their origin and evolution. The incorporation of new researchers allowed a new line of research to begin in which the group has been a national benchmark: applying computational chemical methods to the study of mineral properties and reactivity.