International
Tables for Crystallography Volume D Physical properties of crystals Edited by A. Authier © International Union of Crystallography 2013 
International Tables for Crystallography (2013). Vol. D, ch. 3.4, pp. 527528
Section 3.4.3.6.5. Ferroelastic domain pairs with no compatible domain walls, synoptic table^{a}Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, CZ18221 Prague 8, Czech Republic, and ^{b}Department of Mathematics and Didactics of Mathematics, Technical University of Liberec, Hálkova 6, 461 17 Liberec 1, Czech Republic 
Ferroelastic domain pairs for which condition (3.4.3.54) for the existence of coherent domain walls is violated are listed in Table 3.4.3.7. All these pairs are nontransposable pairs. It is expected that domain walls between ferroelastic domain states would be stressed and would contain dislocations. Dudnik & Shuvalov (1989) have shown that in thin samples, where elastic stresses are reduced, `almost coherent' ferroelastic domain walls may exist.

Example 3.4.3.8. Ferroelastic crystal of langbeinite. Langbeinite K_{2}Mg_{2}(SO_{4})_{3} undergoes a phase transition with symmetry descent that appears in Table 3.4.3.7. The ferroelastic phase has three ferroelastic domain states. Dudnik & Shuvalov (1989) found, in accord with their theoretical predictions, nearly linear `almost coherent' domain walls accompanied by elastic stresses in crystals thinner than 0.5 mm. In thicker crystals, elastic stresses became so large that crystals were cracking and no domain walls were observed.
Similar effects were reported by the same authors for the partial ferroelastic phase of CH_{3}NH_{3}Al(SO_{4})_{2}·12H_{2}O (MASD) with symmetry descent , where ferroelastic domain walls were detected only in thin samples.
References
Dudnik, E. F. & Shuvalov, L. A. (1989). Domain structure and phase boundaries in ferroelastics. Ferroelectrics, 98, 207–234.