Table 3. Correlation between + and motifs observed in HRTEM images of (5b), (7b) and (9b) wagnerites with U (up) and D (down) arc-like arrangements of F, OH of the wagnerite structures projected along c .

Wagnerite	[+ ] sequence	[U D] sequence
(5b)	[+ + + ]	[U U D U D]
(7b)	[+ + + + ]	[U U D U D U D]
	[+ + + ]	[U D U D D U D]
(9b)	[+ + + + + ]	[U U D U D U D U D]