In this section, we provide some examples of high-pressure simulations of bulk materials, i.e., systems that are typically simulated with periodic boundary conditions (PBC). The focus lies on water, silica melts, hydrogen cyanide, hydrides, carbon-rich materials and biological (macro)molecules under pressure. Metals, semi-conductors and non-molecular crystals, for which a large number of studies exist, are not the focus of this review.