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Messages - MalcolmHLevitt

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The obscure bug in ProductKet (only evident for spins > 1/2) has been fixed in the release v2.12.2.

I did not get time to introduce options for alternative "built-in" ZeemanBasis ordering. However instructions for setting up a ZeemanBasis with the same ordering as in the SpinDynamics book are given in part 3 of the documentation accompanying 2.12.2.


Updates and Messages / SpinDynamica 2.12.2
« on: March 05, 2015, 07:54:22 PM »
SpinDynamica 2.12.2 has been released!

download at

Publications / Spin dynamics simulation of electron spin relaxation...
« on: February 07, 2015, 12:17:31 PM »
J. Rantaharju, J. Mareš, J. Vaara, Spin dynamics simulation of electron spin relaxation in Ni(2+)(aq), Journal of Chemical Physics 141, 014109:1-6 (2014), ( ).

Publications / Theory of long-lived nuclear spin states in methyl groups...
« on: February 07, 2015, 12:08:35 PM »
J.-N. Dumez, P. Håkansson, S. Mamone, B. Meier, G. Stevanato, J. T. Hill-Cousins, S. S. Roy, R. C. D. Brown, G. Pileio and M. H. Levitt, “Theory of long-lived nuclear spin states in methyl groups and quantum-rotor induced polarisation,” J. Chem. Phys. 142, 044506 (2015).

An executable SpinDynamica notebook is here:

Bug reports / Re: More of a question: Ordering of Zeeman product states
« on: February 06, 2015, 09:16:05 PM »
Thanks Andreas, I'll have to look into it properly. I'll attempt to introduce a consistent ordering of the ZeemanBasis in the next version.

Bug reports / Re: More of a question: Ordering of Zeeman product states
« on: February 06, 2015, 06:13:51 PM »
OK, I see the problem. A general fix uses this (rather fancy) syntax:

ReorderedKets =
   Sequence @@ Map[BasisKets[ZeemanBasis[{#}]] &, SpinSystem[]]]

I hope to implement this automatically in the next version. To my shame I had not noticed that the ordering of the kets was inconsistent between SpinDynamica and my Spin Dynamics book. Apologies!

a revised notebook is attached


Bug reports / Re: More of a question: Ordering of Zeeman product states
« on: February 06, 2015, 09:10:21 AM »
I expect to implement a built-in way to do this in the next release.


Bug reports / Re: More of a question: Ordering of Zeeman product states
« on: February 05, 2015, 03:26:50 PM »
Hi Andreas,
 there is no built-in way to do this, but the reordering of the basis kets may be accomplished rather easily using SpinPermutationOperator, and a new basis using the reordered kets defined using DefineBasis and used using SetBasis.

In general the permutation has to exchange pairs of spins related by reversing the order, i.e. if the spins are {a, b, c... X, Y, Z} then the appropriate permutation is {{a,Z},{b,Y},{c,X}...}.

An example file is attached. I hope this is clear.


Updates and Messages / SpinDynamica 2.12.1 released
« on: January 28, 2015, 04:48:30 PM »
  • New routine Secularize secularizes operators and superoperators with respect to a general Hamiltonian, with an abbreviated syntax for Zeeman secularization.
  • A Signal object may now be multiplied directly by an complex number, for example to implement phase correction.
  • A new option DigitalFrequencyResolution for Signal1D provides more clarity and flexibility in the handling of time and frequency-domain signals. This is described in the enhanced documentation accompanying this release.
  • Some important bug fixes.
  • extended documentation files now include a section on Signal.

Download here:

Examples / Spin-3/2 dynamics
« on: January 16, 2015, 04:07:33 PM »
A new example file has been posted on
The example file illustrates the spin dynamics of a spin-3/2 system in the presence of weak and strong rf fields. Selective manipulations of the central and satellite transitions are illustrated, including the use of cosine-modulated fields to excite the satellite transitions.

Bug reports / Re: Invalid syntax in SpinDynamica v2.10.1
« on: December 08, 2014, 02:05:34 PM »
This problem has been fixed in SD v2.11.1

Updates and Messages / SpinDynamica 2.11.1
« on: December 08, 2014, 02:03:49 PM »
SpinDynamica 2.11.1 has been released here:

This is a relatively major new release with new functions ProductKet, ProductBra and ProductBasis. See part 3 of the documentation.

Signal1D has been augmented with new functionality allowing direct specification of the number of sampling points and the spectral width. See part 2 of the documentation.

Major speed improvements have been achieved for some calculations.
A variety of minor bugs have been fixed.

Bug reports / Re: Invalid syntax in SpinDynamica v2.10.1
« on: September 29, 2014, 01:45:29 PM »
Thanks Jyrki,
 You're right, the repeated pattern in SpinsOrderedQ[{label_..}] is not parsed by Mathematica, to my surprise.
 I will replace it by the equivalent SpinsOrderedQ[{Repeated[label_]}] in the next release. This does parse correctly, at least in 9.
 I think there is no urgency, since I'm not aware of any real problems being caused by this "Schönheitsfehler" right now.
all the best

Bug reports / Re: Invalid syntax in SpinDynamica v2.10.1
« on: September 26, 2014, 10:20:37 PM »
Hi Jyrki,
 I just saw this bug report, which I had overlooked. However I cannot locate the problem. I encounter no error messages, at least in Mathematica 9. I also do not see an obvious problem with the syntax. Can you clarify please?

Bug reports / Re: opI[].A.opI[] product with SpinDynamica 2.9.1 (and 2.8.3)
« on: September 24, 2014, 10:19:22 PM »
Hi Jyrki, this has been fixed (amongst other things) in SDv2.10.2.

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