Abstract
Crystal Structure of Calcium.—The X-ray pattern obtained with powdered calcium shows that the atoms are arranged in a face-centered cubic lattice. The side of the elementary cube is 5.56 Å. The Ca atoms in Ca have therefore the same arrangement as in CaO and CaF2; but in the fluoride and oxide the atoms are respectively 2 and 14 per cent. closer together than without the fluorine and oxygen.