The underlying theory of MARMOT is described in our technical paper, which also provides examples of the calculation of magnetic properties for different materials.

Fundamentally, MARMOT calculates Weiss fields: effective magnetic fields which create - and are created by - magnetic order. From these Weiss fields, it is possible to extract

• Curie/Néel temperatures
• Magnetization vs. temperature curves
• Magnetic torques resulting from magnetocrystalline anisotropy, at zero and finite temperature
• Parameterizations of the magnetic free energy, for magnetic phase diagrams

The calculation of the Weiss fields is done in the framework of the KKR multiple-scattering theory. MARMOT solves the single-site problem at the scalar-relativistic and full relativistic (four-component Dirac) level. The local self-interaction correction and orbital polarization correction can be applied.

MARMOT works as a post-processing tool on top of scalar-relativistic DFT calculations. Currently the software is interfaced to the HUTSEPOTLink opens in a new window (KKR) and the GPAWLink opens in a new window (wavefunction) DFT codes, and we intend to extend this capability.