The compound (ND4)2[FeCl5(D2O)] has awakened a renewed interest owing to its recent classification as a new multiferroic material. We have recently investigated by means of single crystal neutron diffraction the magnetic structure at zero magnetic field of (ND4)2[FeCl5(D2O)], observing a cycloidal magnetic structure propagating in the c-axis with k = (0, 0, 0.23) and with the magnetic moments lying in the ac plane. Furthermore, we have investigated the influence of pressure in the magnetic structure using CYCLOPS Laue diffractometer. From this previous experiment we have observed a dependence of the magnetic structure with the hydrostatic pressure. The variation of the magnetic structure is closely related with slight variations in the crystal structure, thus monochromatic neutron diffraction is necessary to determine accurately the crystal structure under pressure. Therefore in this proposal we intend to study the effect of moderate pressures in the crystal structure of this compound by means of single crystal neutron diffraction.