New structural model of β-TiO: Superposition of M5X5 superstructures

Unit cells of monoclinic (sp. gr. C2/m) and cubic (sp. gr. Pm3¯m) M5X5 superstructures as well as proposed M(5-11/18)X(5-11/18) superstructure (sp. gr. P1m1). The squares indicate structural vacancies in crystallographic positions of different types.190