Suchergebnisse
Suchergebnisse:
Vor 18 Stunden · 1826 - Moritz Ludwig Frankenheim deriveed the 32 crystal classes by using the crystallographic restriction, consistent with Haüy’s laws, that only 2, 3, 4 and 6-fold rotational axes are permitted. 1830 - Johann F. C. Hessel publishes an independent geometrical derivation of the 32 point groups (crystal classes).
