Examples of screenshots of  Energy program (a part of Fields.exe)

Energy levels Multiline spectrum
Energy levels and simulated spectrum of Fe3+ in LiNbO3. Simulated EPR spectrum with hyperfine interaction of electron with several nuclei.
Random parameter  Naphthalene
Simulation of asymmetry of EPR line due to random distribution of spin-Hamiltonian parameters. Simulated EPR spectrum of naphthalene