EasySpin is a Matlab toolbox for simulating Electron Paramagnetic Resonance (EPR) spectra. It supplements the numerical and visualisation power of Matlab with the best computational methods devised by EPR spectroscopists.

EasySpin is available free of charge. To obtain the toolbox, go to the download page.

Current version: 2.7.1 (12 Feb 2008)

The main tools included are simulation functions for the following types of spectra.

	Isotropic cw EPR spectra one unpaired electron, arbitrary number of nuclei resonance fields are exact (no perturbation formulae) automatic determination of magnetic field range least-squares fitting
	Fast-motion cw EPR spectra one unpaired electron, arbitrary number of nuclei user provides rotational correlation time and tensor anisotropies, line widths are automatically computed least-squares fitting
	Slow-motion cw EPR spectra one unpaired electron, several nuclei axial and orthorhombic rotational diffusion tensor arbitrary tensor orientations orientational potential spin exchange least-squares fitting
	Solid-state cw EPR spectra (powders and crystals) arbitrary number of electron and nuclear spins all interactions, including high-order operators and nuclear quadrupole resonance fields are exact (no perturbation formulae) broadening models: g, A and D strain, unresolved hyperfine splittings non-equilibrium populations perpendicular and parallel detection mode least-squares fitting
	Solid-state ENDOR spectra (powders and crystals) arbitrary number of nuclei, includes nuclear quadrupole hyperfine enhancement built-in orientation selection

Other features include

• Basic spin physics: spin operators, Stevens operators, spin Hamiltonians with arbitrary number of electron and nuclear spins, angular momentum.
• Utilities: line shapes, Euler angle utilities, orientational grids, data import from all common EPR file formats (BES3T, ESP, Varian), nuclear isotope database, field/frequency/g value conversion
• Signal conditioning and analysis: RC filtering, field-modulation, cross-term averaged FFT, moving average, many apodization windows, baseline correction
• Resonances: ENDOR and cw EPR resonance line computations, energy level diagrams
• Time-domain: support for propagators and density matrix evolutions.

EasySpin is written and maintained by Stefan Stoll at the University of California, Davis.

For bug reports, inquiries, additional examples and suggestions, contact the Before submitting bugs, download the latest version and verify them.