The density-driven structural transformations in the calcium silicate glass CaSiO3 will be investigated at pressures increasing to 17.5 GPa. This glass is one of a family of calcium silicate materials that have geophysical importance because they form a significant component of the Earth's mantle. They also have technological applications in e.g. cement. As for SiO2 glass, identifiable changes in the structure are expected to be observed as the density is increased. The results will be used to test molecular dynamics models of calcium silicate glasses and, if necessary, new models will be developed. The results will also provide insight into the possible conformations in compressed high-temperature liquid silicates that are not accessible by crystallographic studies.