In this article we present the synthesis of three-dimensionally ordered ter
nary BC2N crystals produced under high-temperature and high-pressure condit
ions. Unit cell dimensions are a = 2.4820 +/- 0.0007 Angstrom and c = 6.620
+/- 0.003 Angstrom. The composition BC2N is derived from Vegard's law and
quantitative electron energy loss spectroscopy. The ordered arrangement of
atoms in the unit cell is discussed.