Energy filtered CBED patterns of the Cr-stabilized Lit phase of a titanium
tri-aluminide alloy reveal deficit higher order Laue zone (HOLZ) lines in t
he zeroth order diffraction disk, for which the expected 4-mm symmetry is s
ignificantly broken in the < 001 > projection. This apparent break of symme
try may be explained by the presence of lattice strains of order 10(-3). Ef
fects of strain-induced lattice distortions on HOLZ line symmetries are cal
culated by an introduction of rhombohedral, tetragonal or monoclinic distor
tions to the cubic unit cell. It is shown how tensile and shear components
of strain affect the overall HOLZ line symmetries in different ways.