Jessica Bowles

Silicates are a family of materials based on the SiO₄/₂ unit and constitute a large proportion of the Earth’s crust. They are widely used in numerous industries, including glass and cement production, detergent manufacturing, adhesive formulation, and wastewater treatment. Their versatility arises from substantial topological diversity, which gives rise to a broad range of properties. However, this structural complexity also makes it challenging to understand how silicate materials form and behave. A deeper insight into their structures and formation mechanisms could therefore enable new discoveries and practical applications. Experimental Raman spectroscopy has previously been used to study silicates, as it allows in situ measurements. To support the interpretation of these measurements, theoretical prediction of Raman spectra is essential for elucidating the structure and bonding of the system. As an alternative to computational methods based on an explicit description of the electronic structure, such as density functional theory and ab initio molecular dynamics, and to overcome their limited sampling capabilities in time and space, we have attempted to simulate Raman spectra directly from molecular-dynamics trajectories using the polarisable AMOEBA force field. This force field provides a detailed description of electrostatic interactions, which are essential for vibrational spectroscopy, through permanent atomic multipoles and induced atomic dipoles. Building on previous work, this presentation will describe the extension of the Raman-spectroscopy implementation in the Tinker software package to hydrated systems and silicic acids. New force-field parameters have also been introduced to provide a specific description of these species.