Mineral-water interfaces, and, specifically, carbonate minerals, are relevant in a wide range of problems in natural sciences (geophysics, geochemistry) and Society (medicine, and climate change) [1,2]. Carbonate-water interfaces play a key role in many physical and chemical processes: biomineralization [3,4], weathering and soil formation [5,1], carbon sequestration [6,1,2], scale formation, and ore mineral deposition. The investigation of these processes involves a wide range of scales, from nm to macroscopic. The advent of a new body of simulations tools,e.g. ab initio Molecular Dynamics, Monte Carlo, Lattice Boltzmann and rare event sampling techniques [7, 8], has enabled the modelling of nano- and upscale processes at fluid-solid interfaces, the study of nanoparticles and complex macro-molecules and the investigation of nucleation phenomena. These techniques can bring new routes to explain the elementary steps governing nanoscale processes relevant to growth, dissolution and reactive properties of mineral surfaces. A major issue preventing the deployment of these techniques in mineral-water interfaces is the inability of specific methods to cover several length scales. As a result, the studied nano-scale properties are hard to use to interpret the phenomenology at the macro-scale, and vice-versa. We believe that the scientific community requires more comprehensive computational methods to develop accurate models to explain and predict complex mineral processes across the scales.

Cutting-edge experimental approaches have allowed probing nano-scale interactions and composition and in situ dynamics of growth and dissolution. Several experimental techniques (Electron Microscopy, X-ray Photo-Electron Spectroscopy, Atomic Force Microscopy, Vertical Scanning Interferometry, and Surface Force Apparatus) have increased our understanding of surface processes to unprecedented levels [9-12]. However, the description of the dynamics of mineral surfaces lacks a good understanding of the molecular mechanisms associated to surface reactions and the impact these have on surface free energies and crystal growth. Simulation techniques are ideal to complement experiments. Future developments in theory and experiment must advance in parallel.

The primary aim of the Workshop is to bring together scientists working on computational and experimental approaches covering multiscale aspects of mineral surface reactions: growth, nucleation inhibition and chemical and physical processes under nano-confinement conditions, where the reactive system size is limited spatially. We want to stimulate discussions between scientists working across scales: nano, micron and mm-size pores, and from nanoparticles to macroscopic mineral grains. Carbonate minerals, e.g. calcite, will represent a central aspect of these discussions. We will define the state-of-the-art of the field and identify challenges to set up short- and medium-term objectives for the development and deployment of computational tools to assist the design and interpretation of experimental studies. We wish to focus on new avenues involving Density Functional Theory [13], Molecular Dynamics [14,15] , Kinetic Monte Carlo [16], Lattice Boltzmann methods [17,18], and continuum/phase field models [19-21], and asses their suitability to analyze experimental data involving mineral surfaces. This is a truly multiscale problem spanning a wide range of length and time scales.