Electron resonance studies of transition metal oxyions - II. Theory of electron resonance in manganate

It is shown that the detailed electron spin resonance spectrum of the manganate ion, (MnO4)2-, can be explained by assuming that the unpaired electron is in a doubly degenerate molecular orbital of symmetry type E and that the first excited state available to it is triply degenerate of symmetry type T2. The results indicate that the E orbital is largely concentrated on the manganese atom while the T2 orbital is spread over the whole molecule. As a result of this analysis the quadrupole moment of 55Mn is estimated to be 0·2 x 10-24 cm2.