||Several studies in magnetic resonance experiment and theory are presented. The longitudinal relaxation of solid <super>129</super>Xe is shown to have an unexpected structural dependence through experiments that provide previously unattainable reproducibility; also, groundwork is laid for theories that describe the observed data. A history of the field is given, including a theory of nuclear spin relaxation due to the coupling of the spins to the phonon bath, as well as the description of an extension of this theory. Theoretical work is also presented that involves nontraditional methods of magnetic resonance detection, such as optically and electrically detected magnetic resonance in semiconducting material. This work confirms, using computational and theoretical methods, the presence of dipolar coupling between two paramagnetic spin-half states to account for observed behavior in Rabi oscillations resulting in an increase of the Rabi frequency by a factor of 2<super>1/2</super>; however, it is also shown that a strong presence of exchange coupling is required. Additional Rabi oscillation studies are given that involve experimental NMR water data, which confirm predictions of Rabi oscillation beat envelopes in three different regimes of longitudinal field modulation during a magnetic resonance experiment. Ancillary material include results from: a theoretical study of Rb atomic transition strengths, transverse relaxation in dilute-spin solid <super>129</super>Xe, and longitudinal relaxation of gaseous <super>129</super>Xe with regards to practical hyperpolarized <super>129</super>Xe storage.