  We present the results of neutron scattering experiments to study the crystal
and magnetic structures of the Mott-insulating transition metal oxyselenides
Pr2O2M2OSe2 (M = Mn, Fe). The structural role of the non-Kramers Pr3+ ion is
investigated and analysis of Pr3+ crystal field excitations performed.
Long-range order of Pr3+ moments in Pr2O2Fe2OSe2 can be induced by an applied
magnetic field.
