Platelets and the ⟨110⟩a₀/4 {001} stacking fault in diamond

Electron microscopy reveals the presence of {001}-platelets in annealed, nitrogen containing diamond. These extended planar defects give rise to a large displacement of the surrounding material, are correlated with luminescence and optical absorption, and are characterized by the B' vibrational band above the one-phonon maximum. A recent proposal for an atomic structure for these defects is made up from a ⟨110⟩a₀/4 shear in the {001}-plane, resulting in C–C double bonds aligned along ⟨001⟩. We show here that not only is this structure inconsistent with experimental observations, but it is unstable and reconstructs to form a largely passive stacking fault defect which also has properties inconsistent with the platelet.