public class AtomPositionGeometricCenterPBC
implements IAtomPositionDefinition, java.io.Serializable
Calculates the geometric center over a set of atoms. The position of the
atom or child atoms are accumulated and used to compute their
center (unweighted by mass). Calculated center is obtained via the getPosition
This implementation handles molecules that span the periodic boundaries.
The returned position will always be within the boundary.