Einsteinium triiodide is an

iodide An iodide ion is the ion I−. Compounds with iodine in formal oxidation state −1 are called iodides. In everyday life, iodide is most commonly encountered as a component of iodized salt, which many governments mandate. Worldwide, iodine de ...

of the synthetic

actinide The actinide () or actinoid () series encompasses the 15 metallic chemical elements with atomic numbers from 89 to 103, actinium through lawrencium. The actinide series derives its name from the first element in the series, actinium. The info ...

einsteinium Einsteinium is a synthetic element with the symbol Es and atomic number 99. Einsteinium is a member of the actinide series and it is the seventh transuranium element. It was named in honor of Albert Einstein. Einsteinium was discovered as a com ...

which has the

molecular formula In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, ...

EsI₃. This crystalline salt is an amber-coloured solid.Arnold F. Holleman, Nils Wiberg: ''Lehrbuch der Anorganischen Chemie'', 102nd Edition, de Gruyter, Berlin 2007, , p. 1969. It glows red in the dark due to einsteinium's intense radioactivity. It crystallises in the

hexagonal crystal system In crystallography, the hexagonal crystal family is one of the six crystal families, which includes two crystal systems (hexagonal and trigonal) and two lattice systems (hexagonal and rhombohedral). While commonly confused, the trigonal crysta ...

in the

space group In mathematics, physics and chemistry, a space group is the symmetry group of an object in space, usually in three dimensions. The elements of a space group (its symmetry operations) are the rigid transformations of an object that leave it uncha ...

''R'' with the

lattice parameter A lattice constant or lattice parameter is one of the physical dimensions and angles that determine the geometry of the unit cells in a crystal lattice, and is proportional to the distance between atoms in the crystal. A simple cubic crystal has o ...

s ''a'' = 753 pm and ''c'' = 2084.5 pm with six

formula unit In chemistry, a formula unit is the empirical formula of any ionic or covalent network solid compound used as an independent entity for stoichiometric calculations. It is the lowest whole number ratio of ions represented in an ionic compound. E ...

s per

unit cell In geometry, biology, mineralogy and solid state physics, a unit cell is a repeating unit formed by the vectors spanning the points of a lattice. Despite its suggestive name, the unit cell (unlike a unit vector, for example) does not necessaril ...

. Its crystal structure is

isotypic Isostructural chemical compounds have similar chemical structures. " Isomorphous" when used in the relation to crystal structures is not synonymous: in addition to the same atomic connectivity that characterises isostructural compounds, isomorphous ...

with that of

bismuth(III) iodide Bismuth(III) iodide is the inorganic compound with the formula Bi I3. This gray-black salt is the product of the reaction of bismuth and iodine, which once was of interest in qualitative inorganic analysis. Bismuth(III) iodide adopts a disti ...

.J. R. Peterson: "Chemical Properties of Einsteinium: Part II", in: G. T. Seaborg (ed.):
Proceedings of the 'Symposium Commemorating the 25th Anniversary of Elements 99 and 100'
', 23. January 1978; Report LBL-7701, April 1979, pp. 55–64.

References

Further reading