International
Tables for
Crystallography
Volume B
Reciprocal space
Edited by U. Shmueli

International Tables for Crystallography (2006). Vol. B, ch. 4.4, p. 455   | 1 | 2 |

Figure 4.4.3.1 

P. S. Pershana*

aDivision of Engineering and Applied Science and The Physics Department, Harvard University, Cambridge, MA 02138, USA
Correspondence e-mail: pershan@deas.harvard.edu

[Figure 4.4.3.1]
Figure 4.4.3.1

(a) Schematic illustration of the necessary condition for coupling between order parameters when [|{\bf q}_{2}|\;\lt\; 2|{\bf q}_{1}|]; [|{\bf q}| = (|{\bf q}_{2}|^{2} - |{\bf q}_{1}|^{2})^{1/2} = |{\bf q}_{1}| \sin (\alpha)]. (b) Positions of the principal peaks for the indicated smectic-A phases.