Magnetically frustrated materials are unable to adopt the regular long-range ordered states observed in conventional insulating transition metal oxides. Instead they tend to exhibit more exotic magnetic states, often with high degeneracy. The arrangement of magnetic cations M on the cation-ordered double perovskite strutures Ba2MM'O6 produce a geometrically frustrated lattice. We propose to study the interplay between geometric frustration, magnetic order and crystal structure of Ba2MnTeO6 for the first time. This compound has a slightly distorted structure, with strong antiferromagnetic coupling between Mn2+ centres and a magnetic transition around 40K. Neutrons are uniquely able to determine the subtleties of oxide ion displacements and produce magnetic Bragg peaks to probe any long-range antiferromagnetic ordering.