Structure of Antimony and Bismuth. 

 Fia-. l. 



165 



(100) 



3-0?-- 



J 



(110) 





(ill) 



W- -/-J-jr- - 



- -3>76 

 - -2'Zl- 



(110) 



-Z/3- 



(lii) L__^.^5-__4* 





Spacing of Planes of Antimony in Angstrom Units. (10 8 cm.) 



Bismuth. 



Bismuth, like antimony, crystallises in the dihexagonal 

 alternating system (calcite class). The three edges of the 

 rhombohedron meet in the trigonal axis and the angle 

 between any two of the edges is 87° 34/. The angle be- 

 tween the face (111) and (110) is 36° 58', and that between 

 the faces (100) and (111) is 56° 24'. 



Using a bulb with a palladium anticathode the glancing 

 angles for the first order were 



(111) 



(100) 



4° 18' 5° 8' 



Taking the density of bismuth 9*80 grms./cm. 8 , we find 



from these readings that the unit rhomb contains 8 atoms 



and that the length of the side of the unit rhomb is 

 6'52xl0- 8 cm. 



