Abstract: | The Electron Spin Resonance of Mn2+ in natural crystals of hemimorphite was studied at RT, X-band. No fine structure other than the central M = | + 1/2 〉 ⇆ | −1/2 > transition with allowed (Δm = 0) and forbidden (Δm = ±1) hyperfine transitions were observed. The spectrum was fitted with the spin Hamiltonian parameters g = 2.001, A = −84.6 × 10−4 cm−1. The crystal field parameter D was estimated equal to (8 ± 2) × 10−3 cm−1. The most striking result is the size of the hyperfine splitting constant favoring occupancy of sixfold coordinated sites. |