V O L U M E 2 8 , NO. 10, O C T O B E R 1 9 5 6
I'
1635
()ptic (.jrieutatioii, .S = (1; 1' = b ; Z = c. optic .ixiai ,411gle(58c):;.I.). 21', = 18" with neak dispersion
I t u s evideiiced by tilt: appearance of ~iiinierouscracks and i1,regular extinction of crystals.
< u.
LITERATURE CITED (1) Colani, A , Bull. soc. chim. (4) 43, 754-62 (1928).
Lemon yellobv with absorption Z = 1. > X . THERMAL DATA. Decomposition was first observed a t 112' C. Color.
~ V O R done K under the auspices of the Btomic Energy Commission.
137. Tetrasodium Uranyl Tricarbonate, Na4U02(C03)3 R. M. D O U G L A S S , The University of California, Lor Alamos Scientific Laboratory, LOBAlamos, N. M.
c
of tetrasodium iiranyl tricarbonate were prepared by crystallization from a concentrated aqueous solution of sodium carbonate saturated with sodium uranate ( 1 ) .
__
7 RYSTALS
-
Partial Powder X-Ray Diffraction Pattern of Tetrasodium Uranyl Tricarbonate d , A . , 0bsd.a
hkl
CRYSTAL MORPHOLOGY System and Class. Trigonal; probably hexagonal-scalenohedral, possibly ditrigonal-pyramidal (from x-ray observations). S o piezoelectric effect was detected with a Giebe-Scheibe-type apparatus. hxial Element. c / a = 1.376 (measured); 1.373 (calculated from cell dimensions). Habit. Equant, euhedral cryjtals exhibiting prominent { 1012 ) and { i012}, less prominent [ l O l O 1, and poorly developed { 1120 1 and { 1011 ] faces. Twinning and cleaxage not _observed. Polar Angles. (101_0)A (1011) = 32" 11' (measured), 32" 14' (x-ray); (1OiO) A (1012) = 51" 32' (measured), 51' 36' (x-ray).
X-RAYDIFFRACTION DATA Diffraction Symbol. %mP-c-, embracing space groups P3cl (U4,) and P3cl (C:%).
eel1 Dimensions (from Calibrated Lt7eissenberg Photographs). a. = 9.324 & 0.01 A., co = 12.802 2z 0.01 A. Cell volume 963.8 -4.5. Formula Weights per Cell. 1. Formula Weight. 542.08. Density. 3.i34grams per cc. (calculated; weight of unit atomic weight 1.6602 X gram); 3.63 (measured pycnometrically). OPTICAL
PROPERTIES
Uniaxial negative. Refractive Indices (5893 A , ) . no = 1.645 =k 0.001, n~ = 1.531 =k 0.002; geometric mean 1.606. Mean refractive index calculated from specific refractive energies ( 2 ) and calculated density, 1.616. Molecular refraction 50.0 cc. Color. Yellow; pleochroic with 0 strong yelloW, E COlorkSS.
100 002 102
110
200 202 004 210 211 212 300 114 204 220 310 214 312 106 402 200
8,075 6.401 5.016 4.662 4.037 3.415 3.201 3.052 2.9688 2.7549 2.6917 2.6386 2.5087 2.3310 2.2396 2.2087 2.1139 2,0629 1,9253 1,8865
8.068
6.315 5.003 4.662 4.034 3.412 3.196 3.053 2.9689 2.7549 2,6944 2.6367 2.5076 2.3319 2.2396 2.2094 2.1131 2.0627 1.9246 1.8861
1/116 40 7 100
G4 20 44 53
18
27 62 38 15 16 35 11
20 56 40 9 20
.Ibout 70 additional lines observed. a
Philips 114.6-nim.-diameter powder camera. Straumanis mounting:
Relative peak intensities above background from densitometer measurements. b
LITERATURE CITED (1) "Gmelins Handbuch der anorganischen Chemie," 8. Auflage, System-Kummer 55, S. 193, Verlag Chemie, Berlin, 1936. (2) Larsen, E. S., Berman, H., "hIicroscopic Determination of the Konopaque hlinerals," 2nd ed., U. S. Geol. Surv. Bull. 848, 31
(1934). WORK done under the auspices of t h e Atonnc Energy Conjmltslon.
138. Dirubidium Thorium Hexanitrate, R b,Th( NO,), D. I . WALKER,' DON T. C R O M E R , and E U G E N E STARITZKY, The University of California, Los Alamor Scientific Laboratory,
Los Alamor, N. M.
IRUBIDIUM
thorium hexanitrate may be prepared by allowing
D a nitric acid solution containing the component nitratesIt inis
stoichiometric ratio to evaporate a t room temperature. isomorphous with double nitrates of thorium with ammonium and cesium, of cerium with ammonium, potassium, rubidium, cesium, and thallium, and of plutomium with ammonium, potassium, rubidium, and thallium ( 2 ) . ('RYSTAL
21'. After transformation by matrix (OO~/OlO/lOl)to conform to the orientation of the unit cell, this becomes a:b:c = 1.169: 1: 2.247; p = 121' 0'. Habit. Tabular { O l O l with I l O O l , / O O l l . 17021. 10111. Commonly twinned on ( loo} and (102). Twinning is'simple or polysynthetic. I n the latter case the twinned crystals appear as roughly hexagonal plates with three sets of interpenetrating twinning lamellae.
LfORPHOLOGY
X-RAYD I F F R a C T I O N DATA System and Class. Monoclinic, prismatic. Axial Elements. a:b:c = 1.210:1:2.222; p = 121.2' (derived Saace Groua. P 2 .,, / c (C!,). -,., from unit cell dimensions). For the isomorphous ( N H 4 ) 2 C e ( S 0 3 ) 6 cell Dimensions. a. = 8.34 A . ; bo = 6.89 A . ; co = 15.31 h.; des Cloiaeaux ( 1 ) determined a:b:c = 1.926: 1: 1.169; p = 90" @ = 121.2"; cell volume 752.5 4.3. Formula Weights per Cell. 2. Formula Weight. 775.13. 1 Present address, Department of Chemistry. University of Colorado, :%ouldrr,Colo. Density. 3.42 grams per cc. (x-ray) \
