The Crystal Structure of Potassium Permanganate

The crystal structure of potassium permanganate was determined from Laue and x-ray single crystal oscillation photographs. It was found that the unit cell is orthorhombic, contains four molecules, and has the dimensions: $a=9.09\mathrm{}\mathrm{A} b=5.72\mathrm{}\mathrm{A} c=7.41\mathrm{}\mathrm{A}$ The symmetry of the crystal is $2Di-16 \left({V_h}^{16}\right)$, and the structure may be given by the following parameters, expressed as fractions of the unit cell dimensions: The agreement between the observed intensity and the calculated structure amplitude is satisfactory. The crystal, isomorphous with barytes, celestine and anglesite, has a closely similar structure, though the parameters are different. The manganese is surrounded by four oxygen atoms at an average distance of 1.59A, the arrangement being a nearly regular tetrahedron. The average oxygen-to-oxygen distance in a tetrahedron is 2.62A. The smallest distance between oxygens in different tetrahedra is 2.72 A. The potassium is surrounded by nine oxygens at a mean distance of 2.97A.