Manifestation of g-tensor anisotropy in the quantum beats of spin-correlated radical ion pairs

•Radiation-induced fluorescence from frozen tricosane doped with a luminophore was studied.•Magnetic field effect in the fluorescence showed Δg-quantum beats on a nanosecond timescale.•The frequency of the beats increased upon going from the liquid to the crystal phase.•Effect of the g-tensor and hyperfine coupling anisotropy was analysed.•Fast hole migration in the tricosane crystal favoured observation of the beats.