Tensor properties and rotational symmetry of crystals. III. Use of symmetrized components in group 3(3_z)

'Symmetrized' components are introduced in place of the standard ones to improve the method presented in paper I [Fumi & Ripamonti (1980). Acta Cryst. A36, 535-551]. These components, which are simply related to the standard ones, allow a further reduction of the computational task and also a further simplification of the results and of their use. This is illustrated by application to general two-dimensional tensors of ranks 6 and 8 and by particularization of the results to the cases of the third- and fourth-order elastic tensors.