A single XIL function. Because of its deferred-execution scheme, the library is sometimes able to find groups of atoms that it can replace with an optimized routine that does the jobs of all the atoms in the group. These optimized routines are called molecules.

a part of a molecule, which means that it is fully contained in, and governed by, the molecule

a whole which is part of a larger whole--a molecule

a portion of a crease pattern that corresponds to a segment of a single flap within a molecule.

(1) (n.) In the X Imaging Library ( XIL) collection, a single library function call. With the property XILTM library's deferred execution feature, groups of atoms can be combined to create a molecule, which avoids redundant operations.(2) (n.) In the X protocol, a unique numeric identifier that maps to a string name. Atoms identify properties, types, and selections to avoid the overhead of passing arbitrary-length property name strings.

See Molecule.