Molecular crystals—the building blocks that make up many drugs and other products—sometimes take on water molecules, which can alter the crystals in unforeseen ways. Notably, predicting which crystals are likely to contain water and at what level has been difficult and very computationally intensive. This problem is of significant industrial interest, especially in pharmaceuticals, yet the immense challenges associated with it require novel and efficient approaches.
source https://www.lifetechnology.com/blogs/life-technology-science-news/scientists-map-water-in-molecular-crystals-aiding-drug-development