This routine calculates and sets the attributes of all atoms of a given molecule according to their structural properties. In addition, the function returns the number of rings in the molecule. The number of rings is the smallest number of smallest rings.
||If the structure is changed by some method, the atom attributes are not recalculated automatically.
||The function CalcAttributes can process rings which are not larger than MaxRingSize atoms. If the molecule contains any rings larger than MaxRingSize the result is wrong.