Adding all of the diamagnetic susceptibilities for all of the parts of the substance will give you a good approximation for the diamagnetic susceptibility of the substance. Subtracting the diamagnetic susceptibility from the total magnetic susceptibility, X m , gives the susceptiblility due to the paramagnetic part of the molecule, X A . Two other relations for mu effective are as follows. These last two relations allow the number of unpaired electrons to be calculated from the measured paramagnetic susceptibility. If there is cooperative magnetism, a very large magnetic susceptibility can result.
Paramagnetism is a property of a molecule.
Diamagnetism and paramagnetism do not depend on the strength of the magnetic field, whereas antiferromagnetism, ferrimagnetism, and ferromagnetism do depend on the strength of the magnetic field.