ABSTRACT
The angular dependence of spin polarization of the triplet exciton in the A-PMDA single crystals has been investigated by EPR. The most active component of the spin selective populating process of the triplet coincide with the long in-plane axis of the anthracene molecule. Anomalies in the crystal orientations at which the EPR signals of the 0 →+ and—→ 0 transitions change their phases have been observed and discussed.