Changes from release to release

Major new features

• Major overhaul of esfit, it now calculates uncertainties of fitted parameters as well as correlations.
• The new function cardamom simulates dynamic cw EPR spectra from stochastic trajectories, molecular dynamics (MD) trajectories, and Markov-state jump models.
• stochtraj_diffusion and stochtraj_jump calculate stochastic rotational trajectories for Brownian diffusion and discrete jump models.
• chili now supports arbitrary spin systems as well as general orientational potentials (for hindered diffusion).
• saffron now supports general pulse experiments, including shaped pulses.
• spidyan fully integrates the package SPIDYAN for more fundamental spin dynamics simulations.
• A set of new functions provides support for basic manipulations with quaternions: euler2quat, rotmat2quat, quat2euler, quat2rotmat, quatvecmult, quatmult, quatinv.
• wignerd can evaluate single matrix elements for an array of Euler angle sets.
• oripotentialplot plots orientational potentials, as used by chili and cardamom.
• pepper and salt now support spin systems with nucleus-nucleus couplings, given via the spin system field Sys.nn.
• The new function diptensor calculates electron-electron, electron-nucleus and nucleus-nucleus dipolar coupling tensors. It supports anisotropic g tensors.
• isto provides matrix representations of irreducible spherical tensor operators.
• Spin systems now support tilted Stevens tensor operators via fields such as Sys.B2Frame
• Spin systems now support nuclear chemical shielding tensor via the fields Sys.sigma and Sys.sigmaFrame.
• The field Sys.aF in spin systems is no longer supported. Use Sys.B4 and Sys.B4Frame instead.
• Interconvert between spherical and cartesian tensors with the new functions tensor_cart2sph and tensor_sph2cart.
• rotview provides a graphical interface to visualize and explore Euler angles and their associated rotations.
• orca2easyspin supports ORCA5 and can now directly read in the main ORCA output file.
• Photoselection is now supported when simulating EPR spectra of photo-generated species. See function photoselect.
• Significantly extended support for spin-polarized systems (triplets, radical pairs, etc.) in pepper with the new fields Sys.initState.
• cgmatrix has additional input and output options.
• The command easyspin is new. Call easyspin doc to see the documentation. Call easyspin info to display information about the currently installed EasySpin version. Call easyspin compile to compile the C files contained in EasySpin.
• pulse has a new amplitude modulation function tanh2, which adds tanh² roll-offs to the pulse edges.
• The interactive table of nuclear isotopes isotopes has a redesigned interface.
• The syntax for obtaining subspectra from simulation function has changed, the field name in the Opt structure has changed from Opt.Output to Opt.separate and has more options: 'components', 'transitions', 'sites' and 'orientations'. There is extended support for returning subspectra across all EasySpin simulation functions.
• For baseline correction with basecorr, a fitting region can now be provided.
• eulang now calculates Euler angles for a near-orthogonal matrix by first orthogonalizing it using singular-value decomposition.

Major bug fixes

• Fixed problem with strong orientational potentials in chili.
• Improved support for data files from Magnettech spectrometers.
• Improved automatic field range determination in garli.
• curry: Fix wrong weights in powder averages.
• orca2easyspin: Fix inverted tensor frame Euler angles.

Incompatible changes

• The function symm has been renamed to hamsymm.
• To specify spin-polarized system, use Sys.initState instead of Exp.Temperature or Sys.Pop.
• The interface of esfit has changed completely. Refer to the esfit documentation for details.
• The Scaling option of esfit has been removed. Use FitOpt.AutoScale instead.
• The interface of hfine has changed.
• The field Sys.orf (orbital reduction factor) has been removed. Instead, use Sys.gL to specify the orbital g factor, and Sys.soc to specify the strength of the spin-orbit coupling.
• The function rescale has been renamed to rescaledata to avoid conflict with an identically named MATLAB function.
• saffron: The input syntax has changed significantly. See the reference page, the user guide, and the examples.
• chili: The input field name and syntax for orienting potentials has changed. Instead of Sys.lambda, use Sys.Potential. The new input syntax allows the specification of general orientational potentials.
• wignerd input syntax has changed. Instead of providing all three Euler angles in a single array angles, supply them separately as alpha, beta, and gamma.
• The input syntax for dipolar couplings between electron spins has changed. Instead of Sys.eeD, use the new field Sys.dip.
• The function rotatecrystal has been removed. Use Exp.SampleRotation instead.
• sphgrid now returns angles, vectors, and weights together in a structure.
• The function sphtri has been removed; it's functionality is now incorporated into sphgrid.
• The option name to specify powder averages has changed. Instead of Opt.nKnots, use the new field Opt.GridSize.
• easyspininfo and easyspincompile are no longer supported. Use easyspin info and easyspin compile instead. See help for the easyspin command.
• Exp.mwPolarization and Exp.Mode have been removed and replaced with Exp.mwMode.
• The function eigfields has been renamed to resfields_eig.
• To specify the sample orientation, use Exp.SampleFrame. ExpCrystalOrientations is no longer supported. To convert, flip the order and the sign of the angles. Example: Exp.CrystalOrientations = [10 40 -30]*pi/180 is now Exp.SampleFrame = [30 -40 -10]*pi/180.
• The function rotplane has been removed. Use rotateframe instead.
• The third output of pepper, salt, garlic and chili is now a structure instead of a numeric array.
• The function resonatorfunc was renamed to resonatorprofile and extended to return either the transfer function, the voltage reflection coefficient or the power reflection coefficient.
• The function stackplot was updated to allow more flexibility in controlling plot options.
• The oldest supported Matlab version is now R2021b.

Major new features

• Transition-selective spin operators are now available with sop.
• The new function resonator allows to simulate or compensate pulses for the effect of the resonator.
• The new function transmitter allows to simulate or compensate pulses for the effect of amplifier nonlinearity.
• All simulation functions now support multi-isotopologue systems (e.g. natural-abundance isotope mixtures) with equivalent nuclei (given in Sys.n).
• eprload supports new EPR data formats (Adani, Magnettech).
• Spin systems can have nucleus-nucleus couplings (Sys.nn and Sys.nnFrame), and they are incorporated into the spin Hamiltonian (via the new function nnint).
• levelsplot can now plot energies also in reciprocal centimeters (wavenumbers) or electron-volts.
• vec2ang can now take x, y, and z coordinates as separate inputs.

Major bug fixes

• Fixed memory allocation inefficiencies in chili.
• Fixed incorrect bi-quadratic exchange Hamiltonian for >= 4 electron spins (eeint).
• Fixed incorrect file extensions when saving 2D data with eprsave.
• New function exciteprofile calculates pulse excitation profiles from IQ data.
• Fixed incorrect Q tensors when using orca2easyspin.
• Examples for pulse updated.
• Fixed problem with garlic and full g tensors.
• Fixed error in second-order perturbation hyperfine correction for ENDOR, endorfrq_perturb and salt.
• Fixed problem with saffron and crystal simulations.
• Fixed problem with spin multiplicity with orca2easyspin and ORCA 4.0.0.
• Documentation errors corrected.

Incompatible changes

• Function resonator renamed to resonatorfunc.
• Excitation profile calculation moved from pulse to exciteprofile.
• The field Opt.ThetaRange used in salt has been removed.

Major new features

• New functions pulse and exciteprofile that calculate pulse modulation functions and shapes and excitation profiles for a wide range of shaped pulses.
• New function rfmixer that implements up- and downconversion as well as IQ modulation and IQ demodulation.
• New fields Sys.J, Sys.dvec, Sys.eeD to specify isotropic, antisymmetric and symmetric part of the electron-electron coupling.
• saffron now supports several models of RF pulses for Mims ENDOR simulations.
• chili now implements a new method to build the Liouville matrix for arbitrary spin systems (Opt.LiouvMethod).
• evolve now supports multiple detection operators.
• eprsave now supports two-dimensional data sets.
• sop has an new additional input syntax (e.g. sop([1 1 1],'x1y3')).
• sop now includes a no-scaling option (Opt.Scaling='none').
• Isotope data included for Np, Pu, and Am.

Major bug fixes

• saffron: Several bug fixes, including multi-nuclear Mims ENDOR.
• orca2easyspin: Several bug fixes.
• eprload: Fixed problems with Specman import.
• curry: Susceptibility is now correctly in SI units.
• Compatibility with Matlab R2015b.
• chili: Critical bugfix for systems with more than two nuclei or with S>1/2.
• chili: Several other bugfixes.
• chili: Support for multiple electron spins fixed.
• Fix bug in biquadratic exchange term (Sys.ee2).
• Several bugfixes in orca2easyspin

Major new features

• blochsteady is a new function that calculated steady-state solutions of the Bloch equations, useful for rapid scan EPR.
• The function smooth has been renamed to datasmooth.
• esfit can now handle user-defined simulation functions with arbitrary output arguments, through FitOpt.OutArg.
• All fundamental constants are updated to 2014 CODATA recommended values.
• The new function cgmatrix calculates matrices for the transformation between uncoupled and coupled representations in two-spin systems.
• The new function curry can calculate SQUID magnetometer data (magnetic moment and magnetic susceptibility) for arbitrary spin systems.
• EasySpin can now import results from ORCA property calculations using orca2easyspin.
• pepper and garlic now support arbitrary angles between static and microwave magnetic field.
• For cw EPR, microwave radiation can now not only be linearly polarized, but also circularly polarized (left or right) or unpolarized.
• EasySpin can now simulate frequency-swept EPR spectra. All cw-EPR simulation functions (pepper, garlic, chili) support both field-swept or frequency-swept spectra.
• eprload can now import data not only from Bruker, but also from SpecMan, Magnettech, ActiveSpectrum, Adani and JEOL spectrometers.
• New pre-defined fundamental constants: hbar (reduced Planck constant, ℏ=h/2π), mu0 (magnetic constant, vacuum permeability), eps0 (electric constant, vacuum permittivity), evolt (electron volt).
• Improved line shape functions: gaussian can calculate arbitrary high-order derivatives. gaussian and lorentzian can calculate absorption and dispersion line shapes and phase-combine them.
• The new function hilberttrans calculates the Hilbert transform.
• Four-pulse ESEEM is now a predefined experiment in saffron.

Incompatible changes

• The intensities of simulated crystal spectra are scaled up by a factor of 8π² compared to earlier versions. This is to make their intensities consistent with powder spectra.
• In all simulation functions, Exp.Orientations has been replaced by Exp.CrystalOrientations.
• A new frame interface has been implemented. Sys.gpa, Sys.Apa, Sys.Qpa, Sys.Dpa, Sys.eepa, Sys.Diffpa have been replaced by Sys.gFrame, Sys.AFrame, Sys.QFrame, Sys.DFrame, Sys.eeFrame, Sys.DiffFrame. See the documentation on spin systems and on frames.
• In chili, Exp.psi is moved to Sys.psi, and Exp.MOMD is abolished.
• In saffron, Exp.T1T2 is moved to Sys.T1T2.
• Sys.aFrame (frame direction for aF high-order term) renamed to Sys.aFFrame.
• All functions providing Hamiltonians have been renamed to more systematic names: sham to ham, hfine to ham_zf, nquad to ham_nq, zfield to ham_zf, eeint to ham_ee, nnint to ham_nn, soint to ham_so, crystalfield to ham_cf, zeemanho to ham_ezho, and zeeman has been split into ham_ez, ham_nz, and ham_oz.

Major bug fixes

• chili: Crash with large ordering parameters.
• chili: Crash with very large basis sets.
• Improvements in spectral intensity consistency between powders and crystals.
• Improvements in spectral intensity consistency between matrix diagonalization and perturbation theory.

New features

• eprload can now read vector-valued datasets from Bruker BES³T files.

Bug fixes

• salt: Crash with multiple components.
• orisel: Crash with symmetry lower than D2h.

New features

• All Hamiltonian functions now support sparse matrix output (sham, eeint, hfine, nquad, zfield, zeeman).

Bug fixes

• esfit: Crash with MATLAB R2007b.

Bug fixes

• High-order parameter Sys.B2, Sys.B4, Sys.B6: Problems with systems containing multiple S-spins.
• esfit: Crash when using multi-component fits.

Major new features

• High-order spin operators are now supported for spin systems with an arbitrary number of electron spins.

Incompatible changes

• High-order parameter Sys.B40, Sys.B41, Sys.B43 etc have been replaced by Sys.B2, Sys.B4, etc.

Bug fixes

• saffron: did not work correctly with full Q tensor.
• wigner3j: fixed crash for large parameters.
• esfit: fixed scrambled parameter list.

Major new features

• Massively extended interactive least-squares fitting with esfit.
• The new function rescale allows you to fit one spectrum to another by scaling and shifting.
• The new function wignerd computes Wigner D-matrices.
• The new function ewrls computes adaptively filtered averages.
• saffron supports multi-component simulations and space groups .
• pepper supports space groups with perturbation theory.
• saffron supports space groups.
• eprsave can also save the microwave frequency in BES3T format.
• addnoise now includes a simple 1/f noise model.

Changes

• Fundamental constants are updated from the CODATA 2006 to the CODATA 2010 recommended values.
• Support for MATLAB releases prior to R2007b has been dropped.

Bug fixes

• Compatibility adjustment for newest Matlab release R2012a.
• wigner3j and clebschgordan work now for large angular momenta.
• esfit now stays within the specified search range.
• Many small bug fixes.

The following changes are incompatible with older versions and might require adaption of existing code.

• The default axis for Sys.aF was changed from the 3-fold axis to the 4-fold axis. Use Sys.aFrame to change (see reference).
• The overall intensity of spectra returned by garlic has been adjusted to match the intensity of spectra returned by pepper.
• Support for MATLAB releases prior to R2007b has been dropped.

Major new features

• All simulation functions can now simulate multi-component spectra in one go.
• Least-squares fitting of multi-component spectra is supported by esfit.
• The new function eprsave can store datasets in Bruker's EPR format BES3T.
• eprload can explicitly scale data by number of scans, microwave power, receiver gain, temperature, and conversion/sampling time.
• Full D matrices and Q matrices are now supported.
• In systems with several electron spins, D strain can be specified for each spin.
• An isotropic biquadratic exchange interaction term can be added via ee2 in a spin system structure.
• The new function spinladder computes manifold parameters for exchange-coupled spin systems in the strong-exchange limit.
• pepper can now simulate oligometallic clusters with nuclear spins using a new fast hybrid method (Opt.Method='hybrid').
• garlic supports different levels of theory: Opt.Method = 'exact', 'perturb1, 'perturb2'.

Major bugfixes

• voigtian gave wrong line positions.
• Compilation problems on 64-bit Mac computers.
• resfields wasted a lot of memory for large spin systems.
• zfield returned an all-zero Hamiltonian matrix for E/D = 0.

Changes

• Matlab versions prior to 7.0 are not supported anymore.
• Opt.Perturb has been discontinued, use Opt.Method = 'hybrid' instead.
• Exp.Detection has been renamed to Exp.Mode.
• chili: Exchange units changed from Hz to MHz.

Major new features

• pepper and garlic now support absorption/dispersion admixture in the simulation via Exp.mwPhase.

Major bugfixes

• salt spectra gave wrong ENDOR intensities in some cases when using perturbation theory and orientation selection.

Major new features

• pepper and garlic can now include field modulation in the simulation via Exp.ModAmp.

Major bugfixes

• pepper gave incorrect first-order perturbation intensities for large anisotropic g tensors.
• garlic spectra gave double integrals that depended on the number of lines.

The following changes are incompatible and might require adaption of existing code.

• The absolute intensity of some spectra computed by garlic has changed.
• The absolute intensity of the spectra computed by pepper with Opt.Method='perturb' has changed. The intensity now match that of the spectra computed with Opt.Method='matrix'.
• The order of Gaussian and Lorentzian FWHM in the fwhm parameter to the function lshape is reversed.

Several bug fixes in saffron, salt and garlic.

Major bugfixes

• eprload could not read data acquired on very recent Bruker spectrometers.
• garlic gave wrong relative intensities in some isotope mixtures.
• chili used incomplete rotational basis in the case of a tilt between g and A tensors.
• pepper missed a transition in the case of very large hyperfine couplings.
• saffron gave incorrect peak positions in HYSCORE of systems with anisotropic g.

Major new features

• saffron can now simulate spectra for isotope mixtures.

Many small bug fixes.

Major new features

• saffron is not restricted to HYSCORE, two-pulse and three-pulse ESEEM. It can now simulate user-defined pulse sequences.
• saffron now supports the product rule, resulting in great speed-ups.
• saffron now supports spin systems with high electron spin S>1/2.
• salt can now simulate ENDOR spectra using either matrix diagonalization, first-order or second-order perturbation theory.

Major changes and bugfixes

• pepper normalizes spectra in a way that the double integral is independent of the number of nuclei included.

The following changes are incompatible with older versions and might require adaption of existing code.

• The input syntax for endorfrq has changed from (Sys,Exp,Ori,Opt) to (Sys,Exp,Opt). The orientations are now given in Exp.Orientations.

Major new features

• chili now supports the MOMD model for slow-motion simulations.
• pepper now automatically simulates isotope mixtures.
• salt now can use first-order perturbation theory for the simulation, resulting in speed-ups of several orders of magnitude for spin systems with several nuclei compared to matrix diagonalization.
• pepper now can use second-order perturbation theory for the simulation, resulting in speed-ups of several orders of magnitude for spin systems with several nuclei compared to matrix diagonalization.
• A genetic algorithm and hybrid global/local methods are now available for least-squares fitting with esfit.
• The new function saffron simulates pulse EPR spectra.
• Site splitting in crystal spectra is now included in simulations with pepper and salt. Only the space group of the crystal has to be provided.
• rotplane computes sets of orientations for crystal rotations.
• stackplot is a new function that plots several spectra stacked on top of each other.
• To add noise to a simulated spectrum, use addnoise.

Major changes

• Fundamental constants are updated from the CODATA 2002 to the CODATA 2006 recommended set.
• The order of outputs of eprload has changed.
• Opt.nSpline is merged with Opt.GridSize. E.g. instead of setting Opt.GridSize=19 and Opt.nSpline=4, one now sets Opt.GridSize=[19 4].

The following changes are incompatible with older versions and might require adaption of existing code.

• The order of outputs of eprload has changed from [spc,Params,B] to [B,spc,Params].
• The input syntax for resfields and resfields_eig has changed from (Sys,Exp,Ori,Opt) to (Sys,Exp,Opt). The orientations are now given in Exp.Orientations.
• The new function fieldmod replaces the old function pseumod.

Only minor bug fixes.

Major new features

• Least-squares fitting for all types of cw EPR simulations (see esfit).
• Orientational potentials and orthorhombic diffusion tensors available in slow-motion simulations with chili.
• Simplified input for axial g and A tensors: only two principal values instead of three are necessary.
• New function zfsframes to determine the conventional eigenframe orientation plus D and E from a given zero-field splitting tensor.
• New function degree to convert between radians and degrees.
• rcfilt can now handle both and upwards and downwards field sweeps.

Major changes and bugfixes

• Substantial speed-up of simulations on several platforms.
• Updated free g value in gfree to 2006 value.
• The function internal has been removed. Use nquad and zfield instead.
• pseumod now can plot its results.
• Bug in wigner3j fixed that gave wrong values for very large angular momenta.

Major changes and bugfixes

• Fixed a bug in wigner6j.
• Updated nuclear electric quadrupole constants, see nucqmom and the nuclear isotope table.

The following changes are incompatible and might require adaption of existing code.

• chili: The calling syntax for chili has changed: Instead of chili(Sys,Dyn,Exp), use chili(Sys,Exp). All field from the structure Dyn shoud now be set in Sys.
• The function internal has been removed. Use nquad and zfield instead.

Major new features

• pepper now supports antisymmetric exchange coupling between electron spins.
• Simplified input for isotropic g and A tensors and for zero-field splittings.
• Support for high-order parameters a and F added.
• Simulation function now accept either FWHM line widths (lw) or peak-to-peak line widths (lwpp).
• Extended support for partially ordered systems in pepper and salt with the new field Exp.Ordering. A simple orienting potential is built-in, a custom arbitrary orienting potential can be specified.
• Nuclear quadrupole line width contribution for fast-motion simulations with garlic.

Major changes and bugfixes

• EasySpin now runs on 64-bit platforms, too.
• Support for MATLAB 6.1 (R12.1) is discontinued.
• Fixed some crashes of the slow-motion simulation function chili.

Major changes and bugfixes

• Speed-up for chili.
• Bug fixes in chili and garlic: scaling of correlation time.
• Bug fixes in eprload: sometimes wrong abscissa vectors.

The following changes are incompatible and might require adaption of existing code.

• garlic: The meaning of the two numbers in Sys.lw are exchanged. Instead of [LorentzianLw GaussianLw], they now are understood as [GaussianLw LorentzianLw]. This way, the field is identically defined in all simulation functions.
• pepper: The field Opt.LineShape is abolished. The information on Gaussian and Lorentzian lineshapes is now included in Sys.lw. This has the advantages that both Gaussian and Lorentzian broadenings can be specified simultaneously.
• pepper: The field Exp.Nematic is abolished. Instead, a much wider range of possibilities for non-isotropic orientational distributions is available with the field Exp.Ordering.

Major new features

• Simulation of cw EPR spectra in the slow-motional regime with chili.
• Simulation of cw EPR spectra in the fast-motional regime with garlic.
• Two new functions: plegendre for Legendre polynomials and associated Legendre polynomials, and spherharm for spherical and tesseral harmonics.
• Two new functions to convert between rotation axis/angle and rotation matrix: rotaxi2mat and rotmat2axi.
• Two new functions to convert between mT and MHz: mt2mhz and mhz2mt.

Major changes and bugfixes

• Magnetic field ranges can be specified either by the center field and the sweep range (in the field CenterSweep) or by the minimum and the maximum (in the field Range).
• All EPR simulation functions can automatically determine the magnetic field range.
• All simulation functions plot the simulated spectrum, if no output arguments are requested.
• Bug fixes: Non-equilibrium populations in pepper and resfields.

Major new features

• pepper can now treat nuclei with small hyperfine couplings perturbationally, resulting in much better performance for systems with many nuclei.
• pepper and salt can now simulate spectra of paramagnetic species oriented in the nematic phase of liquid crystals.
• Exponential fitting with exponfit.
• makespec constructs a stick spectrum from a list of peak positions and amplitudes.
• Functions to add/remove spins from a spin system: nucspinadd and nucspinrmv.
• Nuclear quadrupole moments and abundance data now available in isotopes, accessible via nucqmom and nucabund. barn gives the unit of quadrupole moments.
• Support for angular momentum algebra: clebschgordan, wigner3j and wigner6j.

Major changes

• The solution EPR simulation function garlic now computes resonance fields using analytical equations rather than perturbation theory formulas.
• sop can now compute multiple spin matrices with a single call.
• New input syntax for orisel.
• stev can now compute extended Stevens operators for arbitrary k and q.
• erot and eulang now accept/return Euler angles optionally as three separate arguments.
• eulang now computes Euler angles from a rotation matrix by least-squares fitting, not via analytical expressions.

• Fixed errors in nuclear isotope database.
• Fixed negative intensity problem in pepper.
• Fixed salt bug resulting in large screen output.

• Spin system structure fields I and gn replaced by new field Nucs
• New simulation function: garlic
• New graphical utilities: eprconvert, isotopes
• Other new functions: deriv, equivcouple, equivsplit, larmorfrq
• Enhanced functions: nucfrq2d, datasmooth
• HTML documentation available for online browsing.
• Many bug fixes.

• Many examples available on EasySpin web site.
• Support for spin systems with an arbitrary number of electron spins.
• resfields and pepper use a new and very robust algorithm for cw resonance field computation.
• pepper and salt support isotropic and single-crystal spectra computation.
• More physical constants, with values and uncertainties.
• eprload reads in the parameter file in addition to the data file.
• New functions: easyspin, levelsplot, apowin, voigtian, basecorr.
• More flexible ctafft.
• Many bug fixes.

• Improved, clarified and corrected documentation, supplemented with many formulas.
• Strict input checking for many functions.
• Many bug fixes.

• New functions: propint, convspec.
• MATLAB version requirements downgraded from 6.1 to 6.0
• If any function with required arguments is called without arguments, the help for this function is displayed.

• resbef renamed to resfields_eig and substantially extended in functionality.
• eulang restrictions relaxed, it now works for matrices with determinant slightly different from 1.
• sop obtains a new and simplified syntax!
• Many bugs fixed.

• Nuclear spin database added. New functions nucdata, nucgval and nucspin.
• Parameter order of evolve has changed.
• For the functions pepper and salt the option parameters Width and Convolution have been eliminated.
• In the spin system specification, flw has been renamed to HStrain.
• resfields and pepper now explicitly exclude NMR transitions.
• salt errors if orientation selection is too strong or the number of knots is not sufficient for reliable results.
• A few EasySpin examples have been added to the package.
• Many bug fixes.

First public release.