Molecular simulation has become an integral and invaluable part of Chemical Product Engineering, as it provides fundamental and indispensable insights for a rational product design. Silica aerogels are materials with exceptional properties and correspondingly broad applications whose study has benefited from this new paradigm. The complex physical/ chemical phenomena involved in their synthesis are hard to explain with experimental data alone. This document reviews relevant atomistic studies regarding silica aerogels, highlighting their contributions to the understanding of the microscopic phenomena inherent to the sol-gel process. Quantum mechanics calculations have provided a framework for investigating the mechanisms, energetics, and products of silica precursor hydrolysis and condensation reactions. Classical molecular dynamics simulations have proven to be suitable for modeling the nanoscale porous network structure of the aerogels, allowing the reliable estimation of structural, mechanical, thermal, and surface properties. Coarse graining models have allowed the extension of these studies to the mesoscale.