General information about the FPLO code version 18
FPLO is an all-electron, Full-Potential, Local-Orbital electronic structure code  using a fixed atomic-like basis set . It allows to treat bulk systems with 3-dimensional periodic boundary conditions and molecules/clusters with free boundary conditions on equal footing, i.e., with the same kind of basis.
Three different iteration schemes allow to converge the Kohn-Sham equations even in critical cases. As a whole, the code is designed for easy handling, high accuracy, efficiency, and stability of the numerics. It allows for calculations with structural units including up to 300 atoms on single-CPU machines.
Relativistic effects are implemented in four different variants (non-relativistic, scalar relativistic [two variants], full relativistic [four component Dirac]) . Optimization of atomic
positions via calculation of forces is implemented for the non-relativistic and for the scalar relativistic modes. The quantization axis is variable in the case of full relativistic spin
LSDA+U and GGA+U are implemented for two different functionals (around mean field and atomic limit, for details see the overview in Ref. ) and for two different projections, in
all four relativistic modes. The orbital polarization correction is implemented in two variants (spin dependent  and spin independent ).
Fixed spin moment calculations  are implemented for all four relativistic modes.
- Finite nuclei;
- Charged systems: virtual crystal approximation, jellium, and molecular charge;
- Open core calculations for 4f systems or simulation of core holes;
- Calculation of optical spectra (not in full relativistic mode);
- De Haas – van Alphen module;
- Scaling of the exchange field (“LSDA•x”);
- Band structure plots on symmetry lines, including so-called fat bands (band weights);
- Band-unfolding for the interpretation of ARPES data;
- Projected densities of states with variable quantization axis;
- Molecular-orbital projected density of states and band weights;
- Wannier function module (maximally projected Wannier functions):
*local spin axes can be defined for each projector;
* spin-mixed relativistic Wannier functions;
- Topological insulators: Z2 invariants for all systems;
- Weyl semi metals: determination of Weyl points;
- Calculation of surface states from Wannier models;
- Module pyfplo for scripting and input manipulation;
- Module xfplo:
* visualization of structures and Fermi surfaces;
* structure and symmetry manipulation;
* cif importer;
* display of Wannier functions and grid output functions (density, spin-density, potential, Bloch wave functions and energy-resolved densities on flexible grids);
* visual Brillouin zone – path construction with automatic point labels for all symmetries in the Fermi surface mode.
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