Changes from release to release
5.2.8
Only minor bug fixes.
5.2.0
Major new features
 Transitionselective 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 multiisotopologue systems (e.g. naturalabundance isotope mixtures) with equivalent nuclei (given in
Sys.n
).
 eprload supports new EPR data formats (Adani, Magnettech).
 Spin systems can have nuclearnuclear 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 electronvolts.
Major bug fixes
 Fixed memory allocation inefficiencies in chili.
 Fixed incorrect biquadratic 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 secondorder 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
5.1.0
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 electronelectron 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 twodimensional data sets.
 sop has an new additional input syntax (e.g.
sop([1 1 1],'x1y3')
).
 sop now includes a noscaling option (
Opt.Scaling='none'
).
 Isotope data included for Np, Pu, and Am.
Major bug fixes
 saffron: Several bug fixes, including multinuclear 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
5.0.0
Major new features
 blochsteady is a new function that calculated steadystate solutions of the Bloch equations, useful for rapid scan EPR.
 The function
smooth
has been renamed to datasmooth.
 esfit can now handle userdefined 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 tranformation between uncoupled and coupled representations in twospin 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 orca2easysin.
 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 frequencyswept EPR spectra. All cwEPR simulation functions (pepper, garlic, chili) support both fieldswept or frequencyswept spectra.
 eprload can now import data not only from Bruker, but also from SpecMan, Magnettech, ActiveSpectrum, Adani and JEOL spectrometers.
 New predefined fundamental constants: hbar (reduced Planck constant, ℏ=h/2π), mu0 (magnetic constant, vacuum permeability), eps0 (electric constant, vacuum permittivity), evolt (electron volt).
 Improved lineshape functions: gaussian can calculate arbitrary highorder derivatives. gaussian and lorentzian can calculate absorption and dispersion line shapes and phasecombine them.
 The new function hilberttrans calculates the Hilbert transform.
 Fourpulse ESEEM is now a predefined experiment in saffron.
Incompatible changes
 The intensities of simulated crystal spectra are scaled up by a factor of 8π^{2} 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.CrystalOrientation
.
 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
highorder term) renamed to Sys.aFFrame
.
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.
4.5.5
New features
 eprload can now read vectorvalued datasets from Bruker BES^{3}T files.
Bug fixes
 salt: Crash with multiple components.
 orisel: Crash with symmetry lower than D2h.
4.5.4
New features
Bug fixes
 esfit: Crash with MATLAB R2007b.
4.5.3
Bug fixes
 Highorder parameter
Sys.B2
, Sys.B4
, Sys.B6
: Problems with systems containing multiple Sspins.
esfit
: Crash when using multicomponent fits.
4.5.2
Major new features
 Highorder spin operators are now supported for spin systems with an arbitrary number of electron spins.
Incompatible changes
 Highorder parameter
Sys.B40
, Sys.B41
, Sys.B43
etc have been replaced by Sys.B2
, Sys.B4
, etc.
4.5.1
Bug fixes
 saffron: did not work correctly with full Q tensor.
 wigner3j: fixed crash for large parameters.
 esfit: fixed scrambled parameter list.
4.5.0
Major new features
 Massively extended interactive leastsquares 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 Dmatrices.
 The new function ewrls computes adaptively filtered averages.
 saffron supports multicomponent 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 adjustement 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 3fold axis to the 4fold 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.
4.0.0
Major new features
 All simulation functions can now simulate multicomponent spectra in one go.
 Leastsquares fitting of multicomponent 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 parametes for exchangecoupled spin systems in the strongexchange 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 64bit Mac computers.
 resfields wasted a lot of memory for large spin systems.
 zfield returned an allzero 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.
3.1.7
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.
3.1.6
Major new features
 pepper and garlic
can now include field modulation in the simulation via
Exp.ModAmp
.
Major bugfixes
 pepper gave incorrect firstorder 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.
3.1.4, 3.1.5
Several bug fixes in saffron, salt and garlic.
3.1.3
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.
3.1.1, 3.1.2
Many small bug fixes.
3.1.0
Major new features
 saffron is not restricted to HYSCORE, twopulse and threepulse ESEEM. It can now simulate userdefined pulse sequences.
 saffron now supports the product rule, resulting in great speedups.
 saffron now supports spin systems with high electron spin S>1/2.
 salt can now simulate ENDOR spectra using either matrix diagonalization, firstorder or secondorder 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
.
3.0.0
Major new features
 chili now supports the MOMD model for slowmotion simulations.
 pepper now automatically simulates isotope mixtures.
 salt now can use firstorder perturbation theory for the simulation, resulting
in speedups of several orders of magnitude for spin systems with several nuclei compared to matrix diagonalization.
 pepper now can use secondorder perturbation theory for the simulation, resulting
in speedups 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 leastsquares 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.nKnots
. E.g. instead of setting Opt.nKnots=19
and Opt.nSpline=4
, one now sets Opt.nKnots=[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 eigfields 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
.
2.7.1
Only minor bug fixes.
2.7.0
Major new features
 Leastsquares fitting for all types of cw EPR simulations (see esfit).

Ordering potentials and orthorhombic diffusion tensors available in slowmotion 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 zerofield 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 speedup 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.
2.6.1
Major changes and bugfixes
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.
2.6.0
Major new features

pepper now supports antisymmetric exchange
coupling between electron spins.

Simplified input for isotropic g and A tensors and for zerofield splittings.

Support for highorder parameters a and F added.

Simulation function now accept either FWHM line widths (
lw
) or
peaktopeak line widths (lwpp
).

Extended support for partially ordered systems in pepper
and salt with the new field
Exp.Ordering
.
A simple orienting potential is builtin, a custom arbitrary orienting potential can be specified.

Nuclear quadrupole line width contribution for fastmotion simulations with
garlic.
Major changes and bugfixes

EasySpin now runs on 64bit platforms, too.

Support for MATLAB 6.1 (R12.1) is discontinued.
 Fixed some crashes of the slowmotion simulation function
chili.
2.5.1
Major changes and bugfixes
 Speedup 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 nonisotropic orientational distributions is available with the field Exp.Ordering
.
2.5.0
Major new features

Simulation of cw EPR spectra in the slowmotional regime with
chili.

Simulation of cw EPR spectra in the fastmotional 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: Nonequilibrium populations in pepper
and resfields.
2.2.0
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 sytem:
nucspinadd and
nucspinrmv.

Nuclear quadrupole moments and abundance data now availabe 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 leastsquares fitting, not via analytical expressions.
2.1.1
 Fixed errors in nuclear isotope database.
 Fixed negative intensity problem in pepper.
 Fixed salt bug resulting in large screen output.
2.1.0
2.0
 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
singlecrystal 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.
1.3.1
 Improved, clarified and corrected documentation, supplemented with many formulas.
 Strict input checking for many functions.
 Many bug fixes.
1.3
 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.
1.2
resbef
renamed to eigfields
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.
1.1
 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.
1.0
First public release.