FLEUR


The FLEUR code is an open-source scientific software package for the simulation of material properties of crystalline solids, thin films, and surfaces. It implements Kohn-Sham density functional theory in terms of the all-electron full-potential linearized augmented-plane-wave method. With this, it is a realization of one of the most precise DFT methodologies. The code has the common features of a modern DFT simulation package. In the past, major applications have been in the field of magnetism, spintronics, quantum materials, e.g. in ultrathin films, complex magnetism like in spin spirals or magnetic Skyrmion lattices, and in spin-orbit related physics, e.g. in graphene and topological insulators.

Simulation model

The physical model used in Fleur simulations is based on the LAPW method, but it is also possible to make use of an APW+lo description. The calculations employ the scalar-relativistic approximation for the kinetic energy operator. Spin-orbit coupling can optionally be included. It is possible to describe noncollinear magnetic structures periodic in the unit cell. The description of spin spirals with deviating periodicity is based on the generalized Bloch theorem. The code offers native support for the description of three-dimensional periodic structures, i.e., bulk crystals, as well as two-dimensional periodic structures like thin films and surfaces. For the description of the exchange-correlation functional different parametrizations for the local density approximation, several generalized-gradient approximations, Hybrid functionals, and partial support for the library are implemented. It is also possible to make use of a DFT+U description.

Features

The Fleur code can be used to directly calculate many different material properties. Among these are:
For the calculation of optical properties Fleur can be combined with the Spex code to perform calculations employing the GW approximation to many-body perturbation theory. Together with the Wannier90 library it is also possible to extract the Kohn-Sham eigenfunctions in terms of Wannier functions.