Actual water structure is a long ongoing scientific research topic (I remember my undergrad biochem professor saying "water... you think it's simple then you learn about transient water structures forming in liquid phase" 20+ years ago) and I still see new articles about techniques being used to probe transient structures in liquid water (https://www.nature.com/articles/379055a0). No need to invoke a fourth phase, liquid water on its own is plenty complicated.