function AddAtom (AtomRec: CTElem):
The method AddAtom adds another atom to the connection table. The parameter AtomRec holds all the information about the atom and its connections. AddAtom returns a TRUE value if the atom has been added successfully.
||The user has to take care, that the content of the element record AtomRec is correct. The addition of incorrectly defined atoms usually leads to strange effects corrupting the connection table. It is therefore recommended to call the method ClearCTElem in order to initialize the atom record.
||The method AddAtom does not resolve cross references within the connection table. This means that the new atom has all the bonds specified but the bonding partners d not have any entries for the bonds to the new atom (the connection table is not symmetric any more). The user should therefore call the method MakeSymmetricConnetions after all atoms have been added to the connection table.