The spin-hamiltonian constant valuations with second order precision

Numerical solutions of the analytic expressions of different spin Hamiltonians are obtained by the method of perturbation theory. In addition, the general form of the spin Hamiltonian matrix is diagonalized by computer. A comparison of the computed estimates obtained by general methods may be used to numerically estimate the capabilities of methods from perturbation theory as a function of the electron spin resonance spectra thin - structure constant evaluation.