Resume This method is the generalization of the application of an experimental technique allowing the study of the zero layer of the reciprocal lattice of large size single crystals set up in our laboratory [1]. It is mainly designed for the study of single crystal samples whose one axis is easily distinguishible. It was, up to now, employed for the study of graphite and its intercalation compounds [2–7]. This method allows one, with 3 rotations around two perpendicular axes, to bring all the hkl reflexions of a single crystal into the goniometer plane. Then, one can determine, for each reflexion, defined by the three angles θ, γ and α (Figs. 1–4): • —the reticular distance (θ). • —the angular shift, in the hkl plane, with respect to a given reference (γy), • —the angular shift of the hkl planes with respect to the corresponding hk0 plane (α). • —the multiplicity factor, • —the intensity. The knowledge of these values allows one to construct the whole reciprocal lattice of the crystal and to assign its space group. As as example, the 210 reflexions of graphite are shown in Fig. 5. In addition, the method can be applied to imperfect crystals (polysynthetic character) whereas a study with an automatic diffractometer can be disturbed by the systematic twining of the crystal. The experimental device is shown in Fig. 6. Our method was applied to the scanning along the hk rods of lamellar compounds[8].