KNaPrTaO5 crystallizes in the tetragonal P4/nmm space group. K(1) is bonded in a square co-planar geometry to four equivalent O(1) atoms. Na(1) is bonded to one O(1) and four equivalent O(2) atoms to form distorted NaO5 trigonal bipyramids that share corners with five equivalent Ta(1)O5 trigonal bipyramids. Pr(1) is bonded in a body-centered cubic geometry to eight equivalent O(2) atoms. Ta(1) is bonded to one O(1) and four equivalent O(2) atoms to form distorted TaO5 trigonal bipyramids that share corners with five equivalent Na(1)O5 trigonal bipyramids. There are two inequivalent O sites. In the first O site, O(1) is bonded to four equivalent K(1), one Na(1), and one Ta(1) atom to form a mixture of distorted edge and corner-sharing OK4NaTa octahedra. The corner-sharing octahedral tilt angles are 11°. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Na(1), two equivalent Pr(1), and one Ta(1) atom.
KNaPrTaO5 crystallizes in the tetragonal P4/nmm space group. K(1) is bonded in a square co-planar geometry to four equivalent O(1) atoms. All K(1)-O(1) bond lengths are 2.92 Å. Na(1) is bonded to one O(1) and four equivalent O(2) atoms to form distorted NaO5 trigonal bipyramids that share corners with five equivalent Ta(1)O5 trigonal bipyramids. The Na(1)-O(1) bond length is 2.28 Å. All Na(1)-O(2) bond lengths are 2.34 Å. Pr(1) is bonded in a body-centered cubic geometry to eight equivalent O(2) atoms. All Pr(1)-O(2) bond lengths are 2.52 Å. Ta(1) is bonded to one O(1) and four equivalent O(2) atoms to form distorted TaO5 trigonal bipyramids that share corners with five equivalent Na(1)O5 trigonal bipyramids. The Ta(1)-O(1) bond length is 1.86 Å. All Ta(1)-O(2) bond lengths are 1.98 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to four equivalent K(1), one Na(1), and one Ta(1) atom to form a mixture of distorted edge and corner-sharing OK4NaTa octahedra. The corner-sharing octahedral tilt angles are 11°. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Na(1), two equivalent Pr(1), and one Ta(1) atom.