Ordinary spin Hamiltonians are used for describing electron paramagnetic resonance spectra in crystals. Expressions are given for the operators which describe the fine structure of the spectra for various types of electric field symmetry cubic, hexagonal, triagonal, tetragonal, ghombic and purely axial. The procedures used for absorption line identification to find the constants of the spin Hamiltonian are discussed. Expressions are given for calculating the hyperfine structure due to interaction between the electron magnetic moment and the magnetic moment of the nucleus of the paramagnetic atom. Experimental research done at the Kazan University on electron paramagnetic resonance spectra in crystals is briefly reviewed. The data on ions with identical effective spins are grouped together. Ions with spins of 12, 32, 52 and 72 are considered. Author
Edited machine trans. of mono. Paramagnitnyi Rezonans, Kazan, 1964 p5-41.