FRITZ-HABER-INSTITUT DER MAX-PLANCK-GESELLSCHAFT, BERLIN-DGHLEM (GERMANY)
Of the seven modifications of ice that are stable at temperatures above -80 "C, modification I has so far been investigated in especially great detail. An eighth modification (ice Ic) which is stable only below -80 "C is also well known. In the following, the crystal lattice structures of these modifications and the formation of mixed crystals are discussed.Received, April 26th, 1962 [A 224/54 [El [I61 E. Cremer: Advances in Catalysis and Related Subjects.