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The all-electron linearized augmented plane wave (LAPW) methods are among the most accurate to solve the Kohn–Sham equations of density functional theory for periodic solids. In the LAPW methods, the unit cell is partitioned into spheres surrounding the atoms, inside which the wave functions are expanded into spherical harmonics, and the interstitial region, where the wave functions are expanded in Fourier series. Recently, Michalicek et al. (2013) reported an analysis of the so-called linearization error, which is inherent to the basis functions inside the spheres, and advocated the use of local orbital basis functions involving the second energy derivative of the radial part (HDLO). In the present work, we report the implementation of such basis functions into the WIEN2k code, and discuss in detail the improvement in terms of accuracy. From our tests, which involve atoms from the whole periodic table, it is concluded that for ground-state properties (e.g., equilibrium volume) the use of HDLO is necessary only for atoms with d or f electrons in the valence and large atomic spheres. For unoccupied states which are not too high above the Fermi energy, HDLO systematically improve the band structure, which may be of importance for the calculation of optical properties. [ABSTRACT FROM AUTHOR]

Abstract: X-ray absorption and its dependence on the polarization of light is a powerful tool to investigate the orbital and spin moments of magnetic materials and their orientation relative to crystalline axes. Here, we present a program for the calculation of dichroic spectra from first principles. We have implemented the calculation of X-ray absorption spectra for left and right circularly polarized light into the Wien2k code. In this package, spin-density functional theory is applied in an all-electron scheme that allows to describe both core and valence electrons on the same footing. The matrix elements, which define the dependence of the photo-absorption cross-section on the polarization of light and on the sample magnetization, are computed within the dipole approximation. Results are presented for the and egdes of CeFe2 and compared to experiments. [Copyright &y& Elsevier]

Abstract: We present an implementation of an interface between the full-potential linearized augmented plane wave package Wien2k and the wannier90 code for the construction of maximally localized Wannier functions. The FORTRAN code and a documentation is made available and results are discussed for SrVO3, Sr2IrO4 (including spin–orbit coupling), LaFeAsO, and FeSb2. [Copyright &y& Elsevier]

Abstract: A new text-based interface for WIEN2k, the full-potential linearized augmented plane-waves (FPLAPW) program, is presented. This code provides an easy to use, yet powerful way of generating arbitrarily large sets of calculations. Thus, properties over a potential energy surface and WIEN2k parameter exploration can be calculated using a simple input text file. This interface also provides new capabilities to the WIEN2k package, such as the calculation of elastic constants on hexagonal systems or the automatic gathering of relevant information. Additionally, runwien is modular, flexible and intuitive. Program summary: Program title: runwien Catalogue identifier: AECM_v1_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AECM_v1_0.html Program obtainable from: CPC Program Library, Queen''s University, Belfast, N. Ireland Licensing provisions: GPL version 3 No. of lines in distributed program, including test data, etc.: 62 567 No. of bytes in distributed program, including test data, etc.: 610 973 Distribution format: tar.gz Programming language: gawk (with locale POSIX or similar) Computer: All running Unix, Linux Operating system: Unix, GNU/Linux Classification: 7.3 External routines: WIEN2k (http://www.wien2k.at/), GAWK (http://www.gnu.org/software/gawk/), rename by L. Wall, a Perl script which renames files, modified by R. Barker to check for the existence of target files, gnuplot (http://www.gnuplot.info/) Subprograms used: Cat Id: ADSY_v1_0/AECB_v1_0, Title: GIBBS/CRITIC, Reference: CPC 158 (2004) 57/CPC 999 (2009) 999 Nature of problem: Creation of a text-based, batch-oriented interface for the WIEN2k package. Solution method: WIEN2k solves the Kohn–Sham equations of a solid using the FPLAPW formalism. Runwien interprets an input file containing the description of the geometry and structure of the solid and drives the execution of the WIEN2k programs. [Copyright &y& Elsevier]

Abstract: In this paper we introduce critic, a new program for the topological analysis of the electron densities of crystalline solids. Two different versions of the code are provided, one adapted to the LAPW (Linear Augmented Plane Wave) density calculated by the WIEN2k package and the other to the ab initio Perturbed Ion (aiPI) density calculated with the pi7 code. Using the converged ground state densities, critic can locate their critical points, determine atomic basins and integrate properties within them, and generate several graphical representations which include topological atomic basins and primary bundles, contour maps of ρ and , vector maps of , chemical graphs, etc. Program summary: Program title: CRITIC Catalogue identifier: AECB_v1_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AECB_v1_0.html Program obtainable from: CPC Program Library, Queen''s University, Belfast, N. Ireland Licensing provisions: GPL, version 3 No. of lines in distributed program, including test data, etc.: 1 206 843 No. of bytes in distributed program, including test data, etc.: 12 648 065 Distribution format: tar.gz Programming language: FORTRAN 77 and 90 Computer: Any computer capable of compiling Fortran Operating system: Unix, GNU/Linux Classification: 7.3 Nature of problem: Topological analysis of the electron density in periodic solids. Solution method: The automatic localization of the electron density critical points is based on a recursive partitioning of the Wigner–Seitz cell into tetrahedra followed by a Newton search from significant points on each tetrahedra. Plotting of and integration on the atomic basins is currently based on a new implementation of Keith''s promega algorithm. Running time: Variable, depending on the task. From seconds to a few minutes for the localization of critical points. Hours to days for the determination of the atomic basins shape and properties. Times correspond to a typical 2007 PC. [Copyright &y& Elsevier]

In studies of the electronic structure of solids, the augmented plane wave (APW) method is the basis for the solution of the Kohn–Sham equations of density functional theory (DFT). The different versions and developing steps are discussed in terms of linearization, full potential, local orbitals, mixed basis sets, relativistic effects and computational aspects, as employed in the WIEN2k code. [Copyright &y& Elsevier]