Mo2P4O15? the most complex oxide structure solved by single crystal methods?

Abstract

We report the crystal structure and phase transitions of Mo2P4O15 which, despite a simple chemical formula, has 441 crystallographically unique atoms in its asymmetric unit and thus has the most complex structure of any extended oxide reported to date.

Complex Superstructures of Mo2P4O15

“…We have briefly reported the low-temperature structure of Mo 2 P 4 -O 15 (hereafter referred to as R-Mo 2 P 4 O 15 or the Pn structure) in an earlier communication. 33 Diffraction images recorded at 120 K required a unit cell considerably larger than the 556 Å 3 monoclinic cell reported by Costentin et al 3 0 1, 0 3 0, -1 0 2), as shown in Figure 4. An automated analysis of systematic absences suggested space group P2 1 /n, though careful inspection showed that reflections forbidden by the 2 1 axis were present though weak.…”

“…We have previously reported the structure of this material at 120 K. 33 In this paper, we report structural studies on Mo 2 P 4 O 15 over a temperature range of 16-731 K which reveal that it is considerably more complex than suggested by earlier work over this entire range. Its low-temperature structure contains 441 atoms in the asymmetric unit, a remarkably high number for a material with such a simple composition.…”

Structural Studies of the System Na(saccharinate)⋅n H2O: A Model for Crystallization

“…The unit cell is large (15 614 3 at room temperature, P2 1 /n, Z = 4), and the above formula gives the number of species (362 atoms, 238 non-hydrogen atoms) in the crystallographic asymmetric unit. The asymmetric unit is not the largest reported, [8] but is still of substantial size and complexity. The 64 Na + cations, 64 sac À anions, and 120 water molecules in the unit cell make this crystal structure one of the largest and most complex ever for ions/molecules that are as small and simple as these.…”

Welche anorganischen Strukturen sind am komplexesten?

“…Ein anderer Ansatz zur Definition von struktureller Komplexität wurde durch Lister et al. formuliert,6b,c die die Zahl der Atome in der asymmetrischen Einheit als ein Maß für die Komplexität einer kommensuraten Struktur benutzten. Diese Methode hat viele Vorteile, bietet aber keine geeignete Quantifizierung der Komplexität hochsymmetrischer Strukturen, wie z.…”