Antimony interatomic distance

The radii in the lowest row of the table were obtained by a number of approximate considerations. For instance, if we assume the bismuth radius to bear the same ratio to the interatomic distance in elementary bismuth as in the case of arsenic and antimony, we obtain (Bi) = 1.16— 1.47 A. A similar conclusion is reached from a study of NiSb and NiBi (with the nickel arsenide structure). Although the structures of the aurous halides have not been determined, it may be pointed out that if they are assumed to be tetrahedral (B3 or Bi) the interatomic distances in the chloride, bromide, and iodide calculated from the observed densities1) are 2.52, 2.66, and 2.75 A, to be compared with 2.19, 2.66, and 2.78 A, respectively, from pur table. 

This type of self-assembly is rather common, because antimony and sulfur form a soft acid-base pair. The Sb-S covalent bond is expected to be ca. 2.4 A (from the sum of the covalent radii) and the van der Waals interatomic distance has been estimated as ca. 4.0 A several self-assembled compoimds with interatomic Sb- - -S distances from 3.0 to slightly less than 4.0 A will be discussed in this section. 

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