( Nuclide ( ( refers ( ( ( to ( a nucleus ) ) ( rather than ) ) ( to ( an atom ) ) ) ) . ) )
(ROOT (S (NP (NNP Nuclide)) (VP (VBZ refers) (PP (PP (TO to) (NP (DT a) (NN nucleus))) (CONJP (RB rather) (IN than)) (PP (TO to) (NP (DT an) (NN atom))))) (. .)))
Nuclide refers to a nucleus rather than to an atom.
(ROOT (S (NP (NP (DT The) (JJ different) (NNS types)) (PP (IN of) (NP (NNS nuclei)))) (VP (VBP are) (VP (VBN referred) (S (VP (TO to))) (PP (IN as) (NP (NNS nuclides))))) (. .)))
The different types of nuclei are referred to as nuclides.