Atom is the smallest particle still characterizing a chemical element.
There is a chemical bond between two atoms or groups of atoms in the case that the forces acting between them are such as to lead to the formation of an aggregate with sufficient stability to make it convenient for the chemist to consider it as an independent 'molecular species'.
Periodic 3D lattice
Molecule is the most important data structure in gchemol, which repsents "any singular entity, irrespective of its nature, used to concisely express any type of chemical particle that can exemplify some process: for example, atoms, molecules, ions, etc. can all undergo a chemical reaction". Molecule may have chemical bonds between atoms.
A container storing extra information managed as key/value pairs
Represents different kind of atom, such as cheimcial element, dummy atom, etc.