As of today, we have new 3D crystal viewer on our materials details pages to replace Jmol, which has served us very well over the last few years.
The motivation for a new viewer is so that we can more tightly integrate with our pymatgen crystallographic analysis package, so that we can resolve a few bugs and inconsistencies that were present with the Jmol version, and to support a more rapid development cycle.
We will have a formal release announcement in the coming weeks. However, until then we are having a soft release to give us time to iron out any bugs during the transition, so please report any issues you may encounter here
Also, if there are any important features from Jmol that you miss, please also tell us so we can prioritize including those features into our new crystal viewer.