elk-lapw

All-Electron Density-Functional Electronic Structure Code

Elk is an all-electron full-potential linearised augmented-plane wave (FP-LAPW) code. By not including pseudo-potentials, Elk can provide very reliable high-precision results and works for every chemical element. Features include: * FP-LAPW basis with local-orbitals * APW radial derivative matching to arbitrary orders at muffin-tin surface (super-LAPW, etc.) * Arbitrary number of local-orbitals allowed (all core states can be made valence for example) * Total energies resolved into components * Forces - including incomplete basis set (IBS) and core corrections work with spin-orbit coupling, non-collinear magnetism and LDA+U * LSDA, GGA and (potential-only) meta-GGA functionals available * LDA+U: fully localised limit (FLL), around mean field (AFM) and interpolation between the two; works with SOC, NCM and spin-spirals * Isolated molecules or periodic systems * Core states treated with the radial Dirac equation * Spin-orbit coupling (SOC) included in second-variational scheme * Non-collinear magnetism (NCM) with arbitrary on-site magnetic fields * Fixed spin-moment calculations (with SOC and NCM) * Time-dependent density functional theory (TDDFT) for linear optical response calculations * First-order optical response * Non-linear optical (NLO) second harmonic generation Elk is parallelized via hybrid OpenMP/OpenMPI.