Godlevskite Ni₉S₈ has been found to be an OD (order-disorder) structure consisting of two kinds of OD layers in strict alternation; these layers display stacking disorder. They have layer symmetries P()2m and P2₁2(2), respectively (symmetry elements in parentheses are perpendicular to OD layers). Two structures with maximum degree of order (MDO polytypes), with space-group symmetries A222 and I4₁22, respectively, exist, together with more complex polytypes or disordered sequences. The OD character is in keeping with the frequent twinning of godlevskite.