From Online Dictionary of Crystallography
Sousmaille (Fr). Unterzelle (Ge). Sottocella (It). 部分単位胞 (Ja). Subcelda (Sp).
A cell C' obtained from a cell C by adding one or more translation vectors of fractional periodicity in C is called a subcell of C. The translation subgroup T' of the lattice L' built on C' is a supergroup of the translation subgroup T of the lattice L built on C and corresponds therefore to a superlattice of L.