#Bi 2 Se 3 #Hexagonal, R3m (166), Z = 3, isostructural with tetradymite, Bi 2Te2 S. The structure #of Bi 2 Se 3 was refined by Nakajima [1963], following earlier work by Semiletov and #Pinsker [1955). #Lattice constants of this sample #a = 4.1396(4)A, c = 28.636(4) #c/a = 6.9176 #Volume 424.97 A3 9.56 4.777 3.559 3.478 3.205 3.183 3.040 2.698 2.534 2.386 2.238 2.106 2.070 1.9085 1.8998 1.8780 1.7893 1.7782 1.7392 1.7349 1.7102 1.6007 1.5909 1.5191 1.4770