This experiment seeks to solve the magnetic structure of a new fluoride Cu3MnFeF12.12D2O, related to the antiperovskite ABX3 ([Mn0.5Fe0.5F6][ Mn0.5Fe0.5F6][Cu(H2O)4]3). Although, the symmetry of its nuclear structure is triclinic with the space group P-1, it can also be described as pseudocubic due to the proximity of the cell parameters. The [MnF6]3- octahedra centered on the B sites of the aniperovskite lattice are linked through the trans-fluoride anions to the [Cu(H2O)4]2+ planar units, thus forming bimetallic chains. These chains run parallel to each crystal axis, giving rise to the final 3D structure. The magnetic interactions between metal ions produce ferrimagnetic behaviour with the Curie temperature of 3K. In this experiment both fully deuterated powder and single crystal will be used in order to avoid strong incoherent scattering produced by protons.