Atom Definition Rules

The definition files use a consistent atom labeling convention for which an atom in virtually any chemical environment can be identified. The specification of adjacent atoms is nested using the elements listed below:

• Each element must be separated by a space.
• If more than one adjacent atom is specified, then ALL must be present (i.e. a boolean AND for rules within a line).
• If a label can have multiple definition lines, then any ONE of them must be satisfied for inclusion (i.e. a boolean OR for rules on different lines).