PrSe2 crystallizes in the tetragonal P-4b2 space group. Pr(1) is bonded in a 9-coordinate geometry to one Se(3), one Se(4), two equivalent Se(2), and five equivalent Se(1) atoms. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded to five equivalent Pr(1) atoms to form a mixture of distorted edge and corner-sharing SePr5 trigonal bipyramids. In the second Se site, Se(2) is bonded in a 7-coordinate geometry to four equivalent Pr(1), one Se(3), and two equivalent Se(4) atoms. In the third Se site, Se(3) is bonded in a distorted hexagonal planar geometry to four equivalent Pr(1) and two equivalent Se(2) atoms. In the fourth Se site, Se(4) is bonded in a 8-coordinate geometry to four equivalent Pr(1) and four equivalent Se(2) atoms.
PrSe2 crystallizes in the tetragonal P-4b2 space group. Pr(1) is bonded in a 9-coordinate geometry to one Se(3), one Se(4), two equivalent Se(2), and five equivalent Se(1) atoms. The Pr(1)-Se(3) bond length is 3.17 Å. The Pr(1)-Se(4) bond length is 3.16 Å. There is one shorter (3.09 Å) and one longer (3.26 Å) Pr(1)-Se(2) bond length. There are a spread of Pr(1)-Se(1) bond distances ranging from 3.03-3.15 Å. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded to five equivalent Pr(1) atoms to form a mixture of distorted edge and corner-sharing SePr5 trigonal bipyramids. In the second Se site, Se(2) is bonded in a 7-coordinate geometry to four equivalent Pr(1), one Se(3), and two equivalent Se(4) atoms. The Se(2)-Se(3) bond length is 2.69 Å. Both Se(2)-Se(4) bond lengths are 2.99 Å. In the third Se site, Se(3) is bonded in a distorted hexagonal planar geometry to four equivalent Pr(1) and two equivalent Se(2) atoms. In the fourth Se site, Se(4) is bonded in a 8-coordinate geometry to four equivalent Pr(1) and four equivalent Se(2) atoms.