Characterization of Radium Sulphate

Table 1

(a) Crystallographic data for barite, celestite, radium sulphate, and anglesite, Table S1, and radium sulphate, [3] and this study. (b) Calculation of mean M–O bond distances based on the ratio of unit cell volumes, using the mean Ba–O bond distance 2.948 Å, Table S2.

(a)

Solid compound	𝑎/Å	𝑏/Å	𝑐/Å	𝑉/Å^3
SrSO4	8.370	5.356	6.867	307.85
BaSO4	8.884	5.459	7.160	347.24
PbSO4	8.488	5.395	6.961	318.76
RaSO4^a	9.07	5.52	7.28	364.48
RaSO4^b	9.16	5.55	7.30	371.12

aThis work. bReference [3].

(b)

Ratio	^3𝑉X/𝑉Ba	Exp. X–O	Det. X–O	Diff
SrSO4/BaSO4	0.9607	2.832	2.826	+0.006
PbSO4/BaSO4	0.9719	2.865	2.864	+0.001
RaSO4^a/BaSO4	1.0163	2.996
RaSO4^b/BaSO4	1.0224	3.014

aThis work. bReference[4].