XtalPaint Restores Missing Hydrogen in Crystal Structures

Hydrogen positions can shape a crystalline material’s electrical, thermal and energy-storage properties, yet the element scatters X-rays weakly and is difficult to locate with conventional diffraction. Neutron measurements can provide better data but require specialized large-scale facilities and are more costly. Crystallographic databases therefore often omit hydrogen atoms or place them using heuristics, creating gaps that can undermine computer simulations and the screening of materials for batteries, hydrogen storage and other applications.

Switzerland’s Paul Scherrer Institute said on June 11, 2026, that its researchers developed XtalPaint by adapting Microsoft’s MatterGen model with TD-Paint, an inpainting technique from computer vision. In tests that removed hydrogen positions from known crystal structures, the open-source system reconstructed the reference arrangement in 87% of cases and found a more energetically stable configuration in another 10%, producing a 97% overall success rate. The researchers said the approach could also be applied to lithium and sodium, two elements central to battery development.