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Nonempirical density functionals investigated for jellium: Spin polarized surfa...
Tao, Jianmin; Perdew, John P.; Almeida, Luís Miguel; Fiolhais, Carlos; Kümmel, StephanJellium, a simple model of metals, is a standard testing ground for density functionals both for bulk and for surface properties. Earlier tests show that the Tao–Perdew–Staroverov–Scuseria (TPSS) nonempirical metageneralized gradient approximation (meta-GGA) for the exchange-correlation energy yields more accurate surface energies than the local spin density (LSD) approximation for spin-unpolarized jellium. In ...
Nonempirical density functionals investigated for jellium: Spin polarized surfa...
Tao, Jianmin; Perdew, John P.; Almeida, Luís Miguel; Fiolhais, Carlos; Kümmel, StephanJellium, a simple model of metals, is a standard testing ground for density functionals both for bulk and for surface properties. Earlier tests show that the Tao–Perdew–Staroverov–Scuseria (TPSS) nonempirical metageneralized gradient approximation (meta-GGA) for the exchange-correlation energy yields more accurate surface energies than the local spin density (LSD) approximation for spin-unpolarized jellium. In ...
Surface and curvature energies from jellium spheres: Density functional hierarc...
Almeida, L. M.; Perdew, John P.; Fiolhais, CarlosWe consider spherical jellium clusters with up to 200 electrons as a testing ground for density functional approximations to the exchange-correlation energy of a many-electron ground state. As nearly-exact standards, we employ Hartree–Fock energies at the exchange-only level and the diffusion Monte Carlo (DMC) energies of Sottile and Ballone (2001) at the correlated level. The density functionals tested are the...
Energy and pressure versus volume: Equations of state motivated by the stabiliz...
Alchagirov, Alim B.; Perdew, John P.; Boettger, Jonathan C.; Albers, R. C.; Fiolhais, CarlosExplicit functions are widely used to interpolate, extrapolate, and differentiate theoretical or experimental data on the equation of state (EOS) of a solid. We present two EOS functions which are theoretically motivated. The simplest realistic model for a simple metal, the stabilized jellium (SJ) or structureless pseudopotential model, is the paradigm for our SJEOS. A simple metal with exponentially overlapped...
Density-functional versus wave-function methods: Toward a benchmark for the jel...
Yan, Zidan; Perdew, John P.; Kurth, Stefan; Fiolhais, Carlos; Almeida, LuísFor the surface energy of jellium at alkali-metal densities, the local-density approximation (LDA) and more advanced density-functional methods disagree strongly with the wave-function-based Fermi hypernetted-chain and diffusion Monte Carlo methods. We present a wave-vector interpolation correction to the generalized gradient approximation which gives jellium surface energies consistent with two other estimates...
Trends in the properties and structures of the simple metals from a universal l...
Nogueira, Fernando; Fiolhais, Carlos; Perdew, John P.The properties of simple metals are fixed primarily by the equilibrium average valence-electron density parameter rs, and secondarily by the valence z. The simplest level of theory that can account quantitatively for these trends invokes a “universal” local electron-ion pseudopotential, defined for each pair (rs,z) and treated as a second-order perturbation. We construct this pseudopotential from two conditions...
Ionization energy and electron affinity of a metal cluster in the stabilized je...
Seidl, Michael; Perdew, John P.; Brajczewska, Marta; Fiolhais, CarlosWe report the first reliable theoretical calculation of the quantum size correction c which yields the asymptotic ionization energy I(R) = W + ((1/2) + c)/R + O(R–2) of a simple-metal cluster of radius R. Restricted-variational electronic density profiles are used to evaluate two sets of expressions for the bulk work function W and quantum size correction c: the Koopmans expressions, and the more accurate and p...
Metal-cluster ionization energy: A profile-insensitive exact expression for the...
Seidl, Michael; Perdew, John P.; Brajczewska, Marta; Fiolhais, CarlosThe ionization energy of a large spherical metal cluster of radius R is I(R)=W+(+c)/R, where W is the bulk work function and c≈-0.1 is a material-dependent quantum correction to the electrostatic size effect. We present 'Koopmans' and 'displaced-profile change-in-self-consistent-field' expressions for W and c within the ordinary and stabilized-jellium models. These expressions are shown to be exact and equivale...
Transferability of a local pseudopotential based on solid-state electron density
Nogueira, Fernando; Fiolhais, Carlos; He, Jingsong; Perdew, John P.; Rubio, AngelLocal electron - ion pseudopotentials fitted to dominant density parameters of the solid state (valence, equilibrium average electron density and interstitial electron density) have been constructed and tested for sixteen simple metals. Calculated solid-state properties present little evidence of the need for pseudopotential non-locality, but this need is increasingly evident as the pseudopotentials are transfe...
Self-expansion and compression of charged clusters of stabilized jellium
Vieira, Armando; Fiolhais, Carlos; Brajczewska, Marta; Perdew, John P.In a positively charged metallic cluster, surface tension tends to enhance the ionic density with respect to its bulk value, while surface-charge repulsion tends to reduce it. Using the stabilized jellium model, we examine the self-expansion and compression of positively charged clusters of simply metals. Quantal results from the Kohn-Sham equations using the local density approximation are compared with contin...
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