Figure 1
(a) MgF2 rutile unit cell. The two Mg atoms are located at (0, 0, 0) and (, , ), and the four F atoms are located at (u, u, 0), (−u, −u, 0), ( + u, − u, ) and ( − u, + u, ). (b) BeF2 α-quartz unit cell. The three Be atoms are located at (x, 0, ), (0, x, ), (−x, −x, 0), and the six F atoms are located at (x, y, z), (−y, x −y, z + ), (−x + y, −x, z + ), (y, x, −z), (x − y, −y, −z + ), (−x, −x + y, −z + ). |