Molecular Networks

Humanity has always been fascinated by the structure and constitution of diverse materials; we have admired and collected gems, precious stones, brightly colored minerals, and crystals for millennia. However, the scientist seeks organizing principles behind the wealth of information collected by our senses (and increasingly nowadays, by instrumentation). We represent these organizing principles as relationships between different objects or materials. These relationships can be of similarity (such as crystals with similar shapes or gemstones with similar color), of transformation (where one material transforms into another upon heating or reacting with water), or of other kinds. Such relationships can be conveniently depicted (both visually and mathematically) as edges of a graph or network. This chapter will provide a brief introduction to molecular networks and different kinds of graphs/networks.