To elaborate on @jeswin's point above (IDK why it got downvoted)... a data structure is basically like a cache for the processing algorithm. The business logic and algorithm needs will dictate what details can be computed on-the-fly -vs- pre-generated and stored (be it RAM or disk). Eg: if you're going to be searching a lot then it makes sense to augment the database with some kind of "index" for fast lookup. Or if you are repeatedly going to be pllotting some derived quantity then maybe it makes sense to derive that once and store with the struct.

It's not enough for a data structure to represent the "fundamental" degrees of freedom needed to model the situation; the algorithmic needs (vis-a-vis the available resources) most definitely matter a lot.