A review of some elements for the history of mechanical twinning centred on its German origins until Otto Mügge’s K 1 and K 2 invariant plane notation

There is a specific nomenclature for the so-called mechanical twins or twins obtained by mechanical deformation. This nomenclature, (K null null null null null null null null null null null null null null null null null null null null null null null 1, η null null null null null null null null null null null null null null null null null null null null null null null 1, K null null null null null null null null null null null null null null...