V O L U M E 2 8 , NO. 5, M A Y 1 9 5 6 unimolecular to the dimolecular rhombohedral cell is - - 3 3 3 1 4 1 1 1 4 B / 3 ~ 3. The volume of the unimolecular rhombohedral 3 cell is 48.26 A? Formula Weight. 115.94. Density. 3.99 grams per cc. (calculated from authors' cell dimensions; weight of unit atomic weight 1.6602 X gram). OPTICALPROPERTIES Uniaxial positive. Refractive Indices (5893 A.). no = 1.703 f 0.003, n E . = 1.726 f 0.004; geometric mean 1.711. Molecular refraction 11.4 cc. Color. 0 brown, E greenish brown. LITERATURE CITED (1) Wyckoff, R. W. G., "Crystal S t r u c t u r e s , " vol. I, chap. V, pp. 12-13, t a b l e pp. 15-16, 1 9 , Interscience, New York, 1951.
WORKdone under the auspices of the Atomic Energy Commission.
915
121. Beryllium Sdfide, BeS EUGENE STARITZKY, The University of California, Los Alamos Scientific Laboratory, Los Alamor, N. M. is prepared by the reaction of beryllium B metal withsulfide hydrogen sulfide a t 900" C. ERYLLIUM
CRYSTAL MORPHOLOGY Isometric, hextetrahedral. Preparations examined consisted of anhedral grains and granular aggregates. X-RAYDIFFRACTION DATA The structure of beryllium sulfide has been determined by Zgchariasen ( 1 ) to be of the sphalerite type. Space group F43m ( E ) . Cell Dimension. a0 = 4.8624 =k 0.0005 A. Cell volume 114.96 A? Zachariasen ( 1 ) reported a0 = 4.86 A. Formula Weights per Cell. 4. Formula Weight. 41.079. Density. 2.373 grams per cc. (x-ray).
-
120. Diberyllium Carbide, Be$ EUGENE STARITZKY, The University of California, Lor Alamos Scientific Laboratory, Los Alamos, N. M. carbide may be prepared by heating beryllium D metal with graphite in neutral atmosphere. IBERYLLImf
a
CRYSTAL NORPHOLOGY Isometric, hesoctahedral. Preparations examined consisted of anhedral grains and granular aggregates.
Powder X-Ray Diffraction Pattern of BeS A., d , A., hkl Calcd. Obsd." 1/11b 2.8073 111 2.807 100 2.4312 2,432 200 31 1.7191 220 39 1.718 1.4661 311 1,466 32 222 1.404 1 ,4037 1; 1.2156 400 1.216 1.1155 1.115 331 13 1.0873 420 1.087 10 0,9925 0.9924 422 13 0.9358 0.9357 333, 511 12 0.8596 0,8595 440 7 0.8219 0.8219 531 18 0,8104 600, 442 0.8104 13 Philips 114.6-mm.-diameter powder camera, Straumanis mounting: X(CuKu) = 1.5418 A . ; X (CuRai) = 1.54050 . 4 : X(CuRae) = 1.54434 A . b Relative peak intensities above background f;om densitometer measurements.
Powder X-Ray Diffraction Pattern of BezC d, A., d , A.; Calcd. Obsd. 1/11b 2.5069 2.502 98 2.171 200 2.1710 1 1.5351 220 1.535 100 311 1.3092 1.309 16 222 1.2534 ,... .. 400 1.0860 1.0855 15 33 1 0.9961 0.9959 7 420 0.9709 0.9709 2 422 0.8863 0.8863 41 333, 511 0.8366 0.8356 11 a Philips 114.6-mm.-diameter powder camera, Straumanis mounting. X(CuKa) = 1.5418 A . ; X(CuKal) = 1.54050 .4. X(CuKuz) = 1.54434 A: b Relative peak intensities above background iiorn densitometer measurements.
hkl 111
X-RAYDIFFRACTIOX DATA The structure of beryllium carbide has been determined by Stackelberg and Quatram ( 1 ) to be of the antifluorite type. Space group Fm3m (0;). Cell Dimension. u o = 4.3420 zk 0.0005 A. Cell volume 81.86 A! Stackelberg ( 1 ) reported a0 = 4.34 A. Formula Weights per Cell. 4. Formula Weight. 30.036. Density. 2.437 grams per cc. (x-ray). OPTICALPROPERTIES Isotropic. Refractive Index (6640 A ) . 2.635 0.010, Molecular refraction 8.19 cc. Colorless. LITERATURE CITED (1) Stackelberg, (1934)
M von, Quatram, F., 2. phys. Chem. (B) 27, 6@2
W o n x done under the auspices of the Atomic Energy Commission.
OPTICALPROPERTIES Isotrouic. Refradtive Index (5893 A.). 2.275 tion 10.07 cc. Colorless.
zk
0.010. Molecular refrac-
LITERATURE CITED (1) Zachariasen, W., 2. phys. Chem. 119, 201-13 (1926).
Won= done under the auspices of the Atomic Energy Commission.
122. Dipotassium Platinum Tetrachloride, K,PtCI, EUGENE STARITZKY, The University of California, Lor Alamos Scientific Laboratory, Lor Alamos, N. M. CRYSTAL MORPHOLOGY System and Class. Tetragonal, ditetragonal-dipyramidal. Axial Elements. The author's observations were in agreement with the axial ratio determined by Nordenskiold ( 3 ) . a : c = 1:0.4161. Transformed by the matrix (llO/T10/002) to correspond to the orientation of the primitive unit cell, this becomes a : c = 1:0.5885. Habit. { 100 1 prisms terminated by ( P O 1 } and ( 101 1 . Polar Angle. (100) A (101) = 59" 31 .
