Quasiatomic orbitals for ab initio tight-binding analysis
نویسندگان
چکیده
Wave functions obtained from plane-wave density-functional theory (DFT) calculations using normconserving pseudopotential, ultrasoft pseudopotential, or projector augmented-wave method are efficiently and robustly transformed into a set of spatially localized nonorthogonal quasiatomic orbitals (QOs) with pseudoangular momentum quantum numbers. We demonstrate that these minimal-basis orbitals can exactly reproduce all the electronic structure information below an energy threshold represented in the form of environment-dependent tight-binding Hamiltonian and overlap matrices. Band structure, density of states, and the Fermi surface are calculated from this real-space tight-binding representation for various extended systems (Si, SiC, Fe, and Mo) and compared with plane-wave DFT results. The Mulliken charge and bond order analyses are performed under QO basis set, which satisfy sum rules. The present work validates the general applicability of Slater and Koster's scheme of linear combinations of atomic orbitals and points to future ab initio tight-binding parametrizations and linear-scaling DFT development.
منابع مشابه
Ab initio tight-binding analysis of CdS nanocrystals
Spherical CdnSm nanocrystals are studied via an ab Initio tight-binding analysis. Starting from the bulk zinc-blende structure, these nanocrystals undergo relaxation as the geometries optimize to configurations that minimize internal forces. The resulting electronic structure and molecular orbitals are analyzed and compared to the electronic structure and molecular orbitals found in the bulklik...
متن کاملCalculating Phase-Coherent Quantum Transport in Nanoelectronics with ab initio Quasiatomic Orbital Basis Set
We present an efficient and accurate computational approach to study phase-coherent quantum transport in molecular and nanoscale electronics. We formulate a Green’s-function method in the recently developed ab initio nonorthogonal quasiatomic orbital basis set within the Landauer-Büttiker formalism. These quasiatomic orbitals are efficiently and robustly transformed from Kohn-Sham eigenwave fun...
متن کاملAll-electron and pseudopotential study of the spin-polarization of the V„001... surface: LDA versus GGA
The spin-polarization at the V~001! surface has been studied by using different local @local spin-density approximation ~LSDA!# and semilocal @generalized gradient approximation ~GGA#! approximations to the exchange-correlation potential of DFT within two ab initio methods: the all-electron tight-binding linear muffin-tin orbital atomic-sphere approximation and the pseudopotential linear combin...
متن کاملMagnetocrystalline anisotropy and orbital polarization in ferromagnetic transition metals
The magnetocrystalline anisotropy energies (MAEs) of the ferromagnetic metals bcc Fe, fcc and hcp Co, and fcc Ni have been calculated by using the ab initio tight-binding method. Disentangling the strong correlation among the d orbitals with the Hamiltonian in the local spin-density approximation, we have investigated the orbital polarizations induced by the Hubbard U and Racah B. The experimen...
متن کاملAb initio molecular simulations with numeric atom-centered orbitals
a r t i c l e i n f o a b s t r a c t Keywords: Ab initio molecular simulations Density-functional theory Atom-centered basis functions Hartree–Fock MP2 O(N) DFT GW self-energy We describe a complete set of algorithms for ab initio molecular simulations based on numerically tabulated atom-centered orbitals (NAOs) to capture a wide range of molecular and materials properties from quantum-mechani...
متن کامل