This code has been written in FORTRAN 2008. It requires one input file that specifies the following:

1. Number of paramagnetic centres in the system.

2. The number of unpaired electrons on each centre.

3. The coupling behaviour between these centres and the coupling strength.

4. The g-value.

5. The strength of the applied magnetic field.

6. The temperature interval and range in which the value of χ and the χT need to determined.

This code generates a .out file that contains the value of χ and the χT product at different temperatures. The output also contains details about the size of Hamiltonian matrix and the M_s values associated with each paramagnetic centre.