Non-Periodic Materials¶
The complete structure of a non-periodic chemcial system is obtained from a set of atoms, known as the basis atoms, that describe a set of non-repeating atoms that are held together by covalent or non-covalent interactions.
This results in a structure with a specific geometry which gives it a defined point-group1 symmetry assignment.
Examples of non-periodic structures include molecules2, like methane3.