Figure 2
Part of the structure as seen from (indicated by the arrow in the upper right part of Fig. 1). Some Bi (small size; black) and O (medium size, light) atoms have been labeled with the numerical parts of their names. Atoms and bonds have been shaded with depth-dependent intensity. Small circles in the right part denote the positions of Sillén & Edstrand's (1942) atoms O1SE [labeled (i) and (iii)] and O8SE [labeled (ii)]. The double arrow at the left denotes a twofold axis. For arrows starting at (i), (ii) and (iii), see text. |