Search found 1030 matches
- Mon Aug 25, 2014 7:14 pm
- Forum: General forum
- Topic: Trouble loading data
- Replies: 2
- Views: 4462
Re: Trouble loading data
What brand and model is the EPR spectrometer you have the data from?
- Mon Aug 18, 2014 2:39 pm
- Forum: General forum
- Topic: Pulsed EPR experiments simulation
- Replies: 2
- Views: 4896
Re: Pulsed EPR experiments simulation
Pulse^2
is a pulse that is twice as long as Pulse
and has twice its flip angle. If you write it out using expm(A)^2 = expm(2*A)
, it should become clear.- Mon Aug 18, 2014 1:48 pm
- Forum: General forum
- Topic: User Specified Populations - experimental.temperature
- Replies: 10
- Views: 13909
Re: User Specified Populations - experimental.temperature
If the coupling between the triplet and the nitroxide is small, then it should still be possible to use Exp.Temperature . You'll need to give populations for all 6 electron manifolds. Something along this should work: clear Sys.S = [1 1/2]; Sys.Nucs = '14N'; Sys.A = [0 0 0, 20 20 80]; Sys.D = [1000 ...
- Mon Aug 18, 2014 11:17 am
- Forum: General forum
- Topic: User Specified Populations - experimental.temperature
- Replies: 10
- Views: 13909
Re: User Specified Populations - experimental.temperature
User-specificed populations in Exp.Temperature have primarily been designed for photoexcited spin-polarized S=1 states: The populations at field are calculated from the populations of the zero-field states , which are given in Exp.Temperature. Here's how the population calculation works currently (a...
- Tue Aug 12, 2014 11:40 am
- Forum: General forum
- Topic: esfit ignores some variables
- Replies: 2
- Views: 5173
Re: esfit ignores some variables
I think I have located the origin of this behavior. Both the LM and the simplex algorithm depend on simulating spectra with slightly different parameters to determine local derivatives in the parameter space (Jacobian for LM, a small simplex for the simplex algorithm). The local derivatives then gui...
- Sat Aug 09, 2014 2:03 pm
- Forum: General forum
- Topic: RMSD from esfit
- Replies: 1
- Views: 4288
Re: RMSD from esfit
In 4.5.5, the simplest way of getting the rmsd after running esfit is [bestSys,bestSpec] = esfit('pepper',expSpec,...) residuals = expSpec - bestSpec; rmsd = sqrt(mean(residuals.^2)) This rmsd is directly based on your experimental data and the best fit, whereas the rmsd displayed by the esfit UI an...
- Mon Jul 28, 2014 5:42 pm
- Forum: General forum
- Topic: Spin-spin interaction
- Replies: 4
- Views: 8205
Re: Spin-spin interaction
Sys.ee includes all forms of electron-electron interactions, no matter what the physical origin is.
Check out the corresponding ES documentation.
Did you mean [-1 -1 2]*270? If yes, this is just the through-space dipolar coupling between two electron spins,
aligned along the z axis.
Check out the corresponding ES documentation.
Did you mean [-1 -1 2]*270? If yes, this is just the through-space dipolar coupling between two electron spins,
aligned along the z axis.
- Mon Jul 28, 2014 5:28 pm
- Forum: General forum
- Topic: esfit and maxTime
- Replies: 8
- Views: 15258
Re: esfit and maxTime
That's an inaccuracy in the documentation. The termination tolerance for Levenberg/Marquardt is FitOpt.TolStep, but for the simplex it is FitOpt.TolEdgeLength: When the edge length of the N+1-dimensional simplex falls below that number, the algorithm will terminate.
I'll fix the documentation.
I'll fix the documentation.
- Mon Jul 28, 2014 5:22 pm
- Forum: General forum
- Topic: Parallelization and esfit
- Replies: 6
- Views: 11682
Re: Parallelization and esfit
Putting some degree of parallelization into ES has been on the to-do list for quite a while. The downside would be that it will require an additional toolbox. I am trying to keep ES running with the (admittedly somewhat feature-anemic) Matlab core.
- Thu Jul 24, 2014 4:12 pm
- Forum: General forum
- Topic: esfit and maxTime
- Replies: 8
- Views: 15258
Re: esfit and maxTime
You are trying to fit N=9 parameters simultaneously. In the simplex algorithm, esfit first computes N+1=10 spectra with slightly different parameter sets within your range to set up what's called the initial simplex. During these setup simulations, esfit does not check FitOpt.maxTime. Only after tha...