Structural chemistry and number theory amalgamized: crystal structure of Na₁₁Hg₅₂

The recently elucidated crystal structure of the technologically important amalgam Na₁₁Hg₅₂ is described by means of a method employing some fundamental concept of number theory, namely modular arithmetical (congruence) relations observed between a slightly idealized set of atomic coordinates. In combination with well known ideas from group theory, regarding lattice–sublattice transformations, these allow for a deeper mutual understanding of both and provide the structural chemist with a slightly different kind of spectacles, thus enabling a distinct viw on complex crystal structures in general.