( ( The ( first region ) ) ( ( consists ( of ( ( cations , ) ( which ( are ( held ( tightly ( to ( the particle ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (JJ first) (NN region)) (VP (VBZ consists) (PP (IN of) (NP (NP (NNS cations)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBP are) (VP (VBN held) (ADVP (RB tightly) (PP (TO to) (NP (DT the) (NN particle))))))))))) (. .)))
The first region consists of cations, which are held tightly to the particle.
(ROOT (S (PP (IN In) (S (VP (VBG naming) (NP (JJ ternary) (NNS compounds))))) (, ,) (NP (DT the) (NN cation)) (VP (VBZ is) (VP (VBN stated) (ADVP (RB first)))) (. .)))