High Field Electron Paramagnetic Resonance (EPR) at the University at Albany (SUNY)
Software development is an important task for any laboratory involved in spectroscopic analysis. Extensions to third-party products, or home-grown software can be useful for this purpose.
Here are some links to useful (external) software packages. There is a strong, and obvious, Python bias.
During periods of fiscal solvency, we also use Matlab packages.
These Matlab codes were used to perform Bayesian inference on multifrequency data sets
We provide utilities for performing angular momentum calculations here. Your comments will help us improve the software.
These codes are useful for exploring curvature effects in a two-dimensional model of the secular g-tensor problem in electron paramagnetic resonance.
Version 1.7 of the EPRLL family of simulation software. Allows computation of spectral derivatives with respect to components of the rotational diffusion tensor, the electron Zeeman interaction and the hyperfine interaction. There is extensive documentation in the UPDATES.DOC and README files on usage. Examples will be found in the sub-directory TESTS
These codes are useful for studying the effect of varying the J-coupling and exchange rate in Quadrupolar relaxation. The model is discussed in Abragam Principles of Nuclear Magnetism. There are two versions of the software: the original octave scripts and a port of the octave scripts to matlab by Nabin Malakar, Dept. of Physics, University at Albany (SUNY).
For Earle Group Python software, e.g., the PythonWignerUtilities, unzip the downloaded folder in a directory on your python path and import the desired function. The Wigner utilities are known to work with Python 2.5 and 2.6. NoteThe zipped archive here fixes a bug, more of a typo, really, in the computation of the Wigner 6j symbols. You may compare the python implementation with the original implementation in Maple V.
The Vision nodes are isofunctional with the python functions in the PythonWignerUtilities package. They are intended to be used in Vision networks, and thus require a separate pre-installation of the MGL Vision package. The MGL Vision package may be downloaded from the Molecular Graphics Laboratory at Scripps. To use the VisionWigUtils package, unzip and install the node scripts in an appropriate folder, e.g., mydefaultlib.other. (see the Vision 'documentation'). There is a README file in the Hamiltonian GUI folder that provides further guidance.
If you encounter problems with Earle Group software, contact us.
The vision nodes and macros are developmental and are not yet known to be stable. We would be grateful for any feed back you can provide on installation and usage issues.
This screen capture shows what the Two Spin Hamiltonian GUI network should look like if launched successfully from Vision. [Screen Capture: Keith Earle]
This screen capture shows the User Panel for the Two Spin Hamiltonian GUI network. By changing the thumbwheel settings, the network evaluates an individual multipole superoperator matrix element. [Screen Capture: Keith Earle]
This screen capture shows the interactive python shell associated with the Two Spin Hamiltonian GUI network. The 'print' node in the Two Spin network echos the multipole superoperator matrix element to the interactive shell. A bug has been fixed in the Commutator Phase node. See discussion below. [Screen Capture: Keith Earle]
This screen capture shows the macro that computes the contribution from the top level couplings of the Two Spin Hamiltonian GUI network. The Commutator Phase node in the Initial macro has an extra factor of 1/2 in the distributed zip files. An updated zip file will be available soon. The adventurous may edit the nodal code to correct this error. [Screen Capture: Keith Earle]
This screen capture shows the Two Spin Hamiltonian GUI Intermediate Macro. It passes on the arguments of the reduced matrix element relevant for computing the proper overall phase in the Commutator Phase node in the Initial Couplings macro. [Screen Capture: Keith Earle]
This screen capture shows the Two Spin Hamiltonian GUI Terminal Macro. This macro computes the major contributions to the reduced matrix element for uncoupled spins at the most primitive level. [Screen Capture: Keith Earle]