Hi Fred,
Any material can be referenced by any of the ids of the computational tasks associated with it. In the case of our stable cubic LuPt3 compound, we have performed a structure optimization task to obtain a relaxed structure, and the task id for this calculation is mp-790.
We customarily use the id of the lowest-energy structure optimization run as the “canonical” id for the material. For this material, the task id for the band structure (line-mode) calculation is mp-994897 (task detail page at https://materialsproject.org/tasks/mp-790#mp-994897). When you navigate to https://materialsproject.org/materials/mp-994897, you should see that the ID at the top of the page for the material is in fact mp-790, as that is the canonical ID for the material.
If you obtain an mp-id and use it to refer to a material, that ID will always “resolve” to that material, even if advances in our calculation methods result in a new task ID being assigned as canonical for a material. I hope this helps.
Best,
Donny
MP team