Recent Posts

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1
Simulations / Re: Simulations of Proton DQ NMR
« Last post by kuprov on April 12, 2020, 07:24:02 PM »
I think this is for the SpinDynamica part of the forum!
2
Examples / Decoupling
« Last post by mariajoseferrer on March 26, 2020, 03:55:32 PM »
Hello,

Is there a way to introduce decoupling in a pulse sequence on SpinDynamica?

3
Simulations / Simulations of Proton DQ NMR
« Last post by zrcrong on March 16, 2020, 07:35:12 AM »
Hi
I am wondering if it is possible to obtain the theoretical analytical forms of proton DQ Hamiltonian for a three spin system.
Currently I am using NPropagate[] commands to do so.
It seems to work properly, but I have no idea how to include the MAS-dependent terms in the proton dipolar Hamiltonian.

Thanks for the help.
4
Updates and Messages / SpinDynamica constant adiabaticity addon
« Last post by Christian Bengs on February 21, 2020, 04:31:01 PM »
I've uploaded a small add on to the SpinDynamica website.

-The add on calculates adiabatic profiles with a constant adiabaticity parameter.
-The function may be used to calculate adiabatic SLIC or APSOC profiles, for example.

See the original publication by our friends from Novosibirsk (Rodin et al., https://doi.org/10.1063/1.5079436) for technical details.

The add on may be found under: http://www.spindynamica.soton.ac.uk/about/addons/
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Bug reports / Preparation with PeriodicFunction[] in Hamiltonian fails
« Last post by Andreas Brinkmann on February 04, 2020, 07:13:06 PM »
Hi Malcolm & Christian,
thanks for releasing version 3.4.2. I noticed that in 3.4.2 Signal1D fails if I have a Hamiltonian with PeriodicFunction[] in the Preparation. The same code works fine in 3.3.1. Please see attached. The workaround by using BackgroundGenerator and a Delay in Preparation works fine.
All the best,
Andreas
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Updates and Messages / SpinDynamica 3.4.2 released!
« Last post by MalcolmHLevitt on February 04, 2020, 04:36:42 PM »
SpinDynamica v3.4.2 has been released.

More bugs have been fixed and the speed improved further. All users should update.
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Updates and Messages / SpinDynamica S(n)/SO(3) dual pairing addon
« Last post by Christian Bengs on January 15, 2020, 12:37:10 PM »
I've just uploaded a small add on to the SpinDynamica website.

-The add on calculates dual-pairings between irreducible representations of S(n) and SO(3) < U(n)
-Irreducible representations of S(n) are identified with Young-Tableaux
-SO(3) irreducible representations are characterised by a total angular momentum quantum number.

Such identifications are useful for the determination of symmetry selection rules for long-lived spin operators.

The add on may be found under: http://www.spindynamica.soton.ac.uk/about/addons/
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Examples / Altadena
« Last post by LaurynasDagys on September 01, 2019, 06:32:20 PM »
The attached simulation shows how to use SpinDynamica to calculate NMR spectrum of the ALTADENA experiment.
The experiment is performed by preparing the singlet spin-order in low-field followed by adiabatic transfer to high-field.

The simulation contains two chapters regarding cases of 2 spins and 3 spins whereas the latter one contains a bit more complexity.

The spectra and matrices were removed from to simulation to save file size but are generated with new evaluation.
9
Simulations / Re: Commutator[], Matrixexponential, Subspace
« Last post by Christian Bengs on February 06, 2019, 10:18:05 AM »
Hey Hannes,

Sorry for the late reply, but I've finally had a quick look at your notebook.

1) There is really no need to let SpinDynamica know what a commutator equals when constructing the matrix representation of a superoperator. The commutation relations will be dealt with "automatically".

2) There is really no way to reduce the size of the matrix unless your Hamiltonian might display some symmetry. In this case you can define your own basis and focus on the relevant subspace. A useful syntax to order the matrix into its subspaces is as follows:

Flatten[ConnectedComponents[Rule @@@MatrixRepresentation[H]]["NonzeroPositions"]]]

This will return a permutation that permutes the Hamiltonian into block-diagonal form.

3) The reason the last calculation doesn't stop is because the analytic calculation of the matrix exponential takes very long. You may circumvent the problem by first calculating the matrix exponential in a "simple" basis and then transform back into your preferred basis.

4) Unfortunately SpinDynamica has no capabilities to restrict calculations to a certain subspace atm.

kind regards,

Christian
10
Updates and Messages / SpinDynamica 3.3.2 released
« Last post by Christian Bengs on February 06, 2019, 10:10:47 AM »
SpinDynamica 3.3.2 has been released.

–EigenBasis now takes TargetBasis as an optional argument. The calculated EigenBasis and TargetBasis will be aligned as closely as possible. This should be useful for analysis of adiabatic calculations.
–Some bug fixes and speed improvements to the basis construction of spins with I>1/2.
–The functions SingleTransitionOperator, CoherenceOperator and PopulationOperator now allow for specification of a basis. See the documentation for more details.

Check out the SpinDynamica website for the new release: http://www.spindynamica.soton.ac.uk/2019/02/06/spindynamica-3-3-2/

or download the new version here: http://blog.soton.ac.uk/spindynamica/download/spindynamica-3-3-2/?wpdmdl=1034
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