Se is alpha-like structured and crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four cyclooctaselenium molecules. There are eight inequivalent Se sites. In the first Se site, Se(1) is bonded in a water-like geometry to one Se(2) and one Se(8) atom. In the second Se site, Se(2) is bonded in a water-like geometry to one Se(1) and one Se(3) atom. In the third Se site, Se(3) is bonded in a water-like geometry to one Se(2) and one Se(4) atom. In the fourth Se site, Se(4) is bonded in a water-like geometry to one Se(3) and one Se(5) atom. In the fifth Se site, Se(5) is bonded in a water-like geometry to one Se(4) and one Se(6) atom. In the sixth Se site, Se(6) is bonded in a water-like geometry to one Se(5) and one Se(7) atom. In the seventh Se site, Se(7) is bonded in a water-like geometry to one Se(6) and one Se(8) atom. In the eighth Se site, Se(8) is bonded in a water-like geometry to one Se(1) and one Se(7) atom.
Se is alpha-like structured and crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four cyclooctaselenium molecules. There are eight inequivalent Se sites. In the first Se site, Se(1) is bonded in a water-like geometry to one Se(2) and one Se(8) atom. The Se(1)-Se(2) bond length is 2.34 Å. The Se(1)-Se(8) bond length is 2.34 Å. In the second Se site, Se(2) is bonded in a water-like geometry to one Se(1) and one Se(3) atom. The Se(2)-Se(3) bond length is 2.34 Å. In the third Se site, Se(3) is bonded in a water-like geometry to one Se(2) and one Se(4) atom. The Se(3)-Se(4) bond length is 2.36 Å. In the fourth Se site, Se(4) is bonded in a water-like geometry to one Se(3) and one Se(5) atom. The Se(4)-Se(5) bond length is 2.34 Å. In the fifth Se site, Se(5) is bonded in a water-like geometry to one Se(4) and one Se(6) atom. The Se(5)-Se(6) bond length is 2.33 Å. In the sixth Se site, Se(6) is bonded in a water-like geometry to one Se(5) and one Se(7) atom. The Se(6)-Se(7) bond length is 2.35 Å. In the seventh Se site, Se(7) is bonded in a water-like geometry to one Se(6) and one Se(8) atom. The Se(7)-Se(8) bond length is 2.34 Å. In the eighth Se site, Se(8) is bonded in a water-like geometry to one Se(1) and one Se(7) atom.