AI model fills in the gaps in crystal structures by placing missing hydrogen atoms

An artificial intelligence (AI) model is able to fill in missing or incorrectly placed atoms – such as hydrogen – in the crystal structures of inorganic materials. Refining atomic positions in this way may allow chemists to better simulate material structures or help design new materials, such as superconductors.

Determining the positions of hydrogen and other small atoms in crystalline materials is challenging as these species scatter x-rays weakly, meaning techniques such as x-ray powder diffraction can lead to inaccurate structures. While neutron or synchrotron diffraction experiments are more accurate, these require access to large facilities, require more material and are expensive to run.