We present in Figure the histogram of occurrence of the most common 3D topologies in the Materials Project database, while Table summarizes key properties of the 16 most common named 3D net topologies. It is not surprising that the most common topologies are very familiar to solid state chemists, including various cubic-based structures (pcu, bcu, and fcu), hexagonal closest packing (hcp), as well as topologies from very common families of materials such as perovskites, spinels, rutile, diamond, etc. Also unsurprisingly, the most common coordination environments include vertices with 4, 6, 8 and 12 neighbors... and less often, coordination numbers of 3, 10 and 16.