As emphasized in the theoretical section, the connection between a single variant of martensite and the parent austenitic phase is provided by a twinned martensitic structure, which is able to satisfy the compatibility conditions
both with the austenite (over the habit plane) and with the single variant.
0]), which are specified through the compatibility conditions of (2.
x] and are determined through compatibility conditions of the overdetermined system composed of (3.
where the functions [phi], [psi] and [lambda] may be determined through compatibility conditions.
The compatibility conditions
(continuity of the body in the deformed state), in conjunction with the mentioned symmetry conditions, mean that in the deformed state the basic cell must keep its rectangular shape.