The FIT-MART Launcher package is a self-contained file for simulating systems of interacting quantum magnetic moments ("spins").  The interactions are modeled using the Heisenberg model, calculations are carried out by numerically diagonalizing the matrix representation of the Heisenberg Hamiltonian, and several types of plots are generated to describe various aspects of the model.

The FIT-MART package is a "Fully Integrated Tool for Magnetic Analysis in Research & Teaching" (hence the acronym) which provides a very simple interface for defining complex quantum spin models, carrying out complex calculations, and visualizing the results using several graphical representations.  These representations include plots of the energy spectrum as well as plots of the magnetization and magnetic susceptibility as a function of temperature and magnetic field.

The FIT-MART package is an Open Source Physics package written to help students as well as researchers who are studying magnetism.  It is distributed as a ready-to-run (compiled) Java archive.  Double clicking osp_fit_mart.jar file will run the package if Java is installed.  In future versions of this package, curricular materials will be included to help students to learn about magnetism, and automated fitting routines will be included to help researchers quickly and easily model experimental data.

Note: An EJS implementation of this program with additional capabilites is available.  <
http://www.compadre.org/osp/items/detail.cfm?ID=12308>

Please note that this resource requires at least version 1.5 of Java.