Download SDv3.7.1 here. This release includes: Compatibility with Mathematica version 13.1. i.e. conflict between the SpinDynamica BlockDiagonalMatrix symbol and the Mathematica symbol of the same name has been resolved Compatibility with Mathematica version 13.0 remains.
Erroneous results have been reported when using SpinDynamica v3.6.x with Mathematica version 13. This is very surprising behaviour since Mathematica should be backwards compatible. This has been pinned down to a surprising inconsistency in the handling of SparseArray objects between Mathematica versions 12 and 13. A bug report has been submitted to wolfram.com. SpinDynamica v3.7 …