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The Dmfit programs enables fitting of solid state (and liquid) NMR spectra, including 1D and 2D datasets
current version is : dmfit#20200306 [Download...
] 
The "dmfit" program is is a versatile tool
designed for fitting NMR spectra, including solid state NMR. It
provides a variety of different models that account for :

Gaussian/Lorentzian lines,
 spinning
sidebands,
 Chemical Shift
Anisotropy (static and MAS),
 first and second
order Quadrupolar interaction (static and MAS)
 ...
New Features...

from #20200306 : solves a bug leading to crash when "load other fit"

from #20191211 : read data with long filenames (>128 characters)...

from #20191202 : read double precision TopSpin4.0 format (Neo Consoles)...

from #20121202 : create .fmxl from CASTEP .magres Have a look...

Error from MonteCarlo : Have a look...
report bugs on the
Bug report page...
Optimisation Algorithm
The mismatch criterion that we use is a simple quadratic distance between the
experimental and modelled spectrum. This could of course be improved in some
cases but its advantage is to make no hypothesis upon the type of data that we
consider. The optimisation algorithm aims at minimizing the mismatch criterion
by varying the parameters of the different lines. As the computation of the
model includes nonlinear dependencies to the different parameters and, in some
cases, no simple analytical form, we use an iterative algorithm. Starting with
an approximate solution we compute and add an increment to try to converge to a
local minimum. This does not ensure the unicity of the obtained solution that
will only be the closest to the starting point. The algorithm used in our
program is a constraint gradient protocol which involves computation of the
partial derivatives over each of the parameters for all variable parameters and
each point of the experimental spectrum. The resolution of the nlinear system
of equation yields an increment that is finally added to the starting parameter
set. This procedure is rather robust when close to a final well defined.
Acknowledgements
Massiot et al. Magnetic Resonance in Chemistry, 40 pp7076 (2002) [
see more or ask for a reprint]
 8518 users with download
"One of the most cited recent paper in the field of Engineering" ISI July 2003
we thank all "dmfit" users for this achievement