Jx support the following features:
J in momentum space.
MFT is a linear response calculation and can be performed in momentum space. Therefore, MFT can compute short and long-term interactions in moment space, without multiple real space supercells calculations.
J coupling matrix (Orbital resolved interactions)
A useful feature of MFT is to calculate the orbitally decomposed magnetic response function. It means that a magnetic coupling constant is extended to a matrix. If we consider d orbital system, for example, each magnetic atom has five magnetic orbitals and the magnetic coupling J12 (in between atom 1 and atom 2) is expressed by a 5X5 matrix J12.
Local axis redefinition for orbital resolved J
In practice, a difficulty in analyzing magnetic materials arises from the absence of well-defined global coordinate axis.
A typical example is the distorted oxides in which the local
x,y,z coordinate at one site is not the same at another. When one tries to calculate the orbital-dependent magnetic coupling, this ambiguity can cause annoying problems. With this motivation, Jx provides functionality for the user to re-define the local coordinates.
Support mulitple Tight-binding Hamiltonian
Basically, any tight-binding style Hamiltonian could be utilized for Jx. Currently we support following interfaces:
- Full DFT Hamiltonian from OpenMX
- Full DFT/QSGW Hamiltonian from EcalJ