The structure and stability of small copper clusters with up to ten atoms has been determined both for the neutral and the ionic clusters with density functional calculations. The calculations were of all-electron type. The structure optimization and frequency analysis were performed on the local density approximation level with the exchange correlation functional by Vosko, Wilk, and Nusair. Subsequently improved calculations for the stability were based on the generalized gradient approximation, where the exchange correlation functional of Perdew and Wang was used. Finally, the binding energies, ionization potentials, electron affinities, and separation energies were calculated. The results show that the trends are in agreement with available experimental data.

Density functional theory optimized basis sets for gradient corrected functionals for 3d transition metal atoms are presented. Double zeta valence polarization and triple zeta valence polarization basis sets are optimized with the PW86 functional. The performance of the newly optimized basis sets is tested in atomic and molecular calculations. Excitation energies of 3d transition metal atoms, as well as electronic configurations, structural parameters, dissociation energies, and harmonic vibrational frequencies of a large number of molecules containing 3d transition metal elements, are presented. The obtained results are compared with available experimental data as well as with other theoretical data from the literature.

Density functional calculations have been performed for small copper clusters, Cun (n≤5), using the linear combination of Gaussian-type orbitals density functional theory (LCGTO-DFT) approach. The calculations were of the all-electron type and local and nonlocal functionals were used. For each case, of both neutral and charged systems, several isomers have been considered in order to determine the lowest energy structures. The Jahn–Teller effect in Cu3 and Cu4 has been examined in detail. Bond lengths, equilibrium geometries, harmonic frequencies, adiabatic and vertical ionization potentials, adiabatic electron affinities, and binding energies are in reasonable agreement with experimental data, as well as with other theoretical results.

International audienceThis article provides a brief overview of the quantum chemical auxiliary density functional theory program deMon2k. A basic introduction into its key computational features is given. By selected examples, it is shown how deMon2k can contribute to the elucidation of problems in chemistry, biology, and materials science such as finite temperature effects, nuclear magnetic resonance studies, structure determinations, heterogeneous, and enzymatic catalysi

This paper presents dipole moments, static polarizabilities, first hyperpolarizabilities and second hyperpolarizabilities calculated in the framework of density functional theory. All calculations have been performed using a finite field approach implemented in our new density functional theory program ALLCHEM. The calculations were of all-electron type. Both local and gradient-corrected functionals have been used. The influence of first- and second-order field-induced polarization functions, the external field strength, the numerical integration technique and the exchange-correlation functionals on the calculation of polarizabilities and hyperpolarizabilities is discussed in detail. A systematic study including 23 small and medium size molecules demonstrates that the obtained polarizabilities as well as the first and second hyperpolarizabilities are in good qualitative agreement with experimental data. The described density functional method provides polarizabilities and hyperpolarizabilities considerably better than the Hartree–Fock method and almost as accurate as much more expensive correlation treatments. This work demonstrates that reliable predictions of electro-optical properties for molecules with 20 and more atoms are possible using an efficient implementation of density functional theory.

First-principles electronic structure calculations within a gradient corrected density functional formalism have been carried out to investigate the electronic structure and magnetic properties of Pd(13) clusters. It is shown that a bilayer ground-state structure that can be regarded as a relaxed bulk fragment is most compatible with the experimental results from Stern-Gerlach measurements. An icosahedral structure, considered to be the ground state in numerous previous studies, is shown to be around 0.14 eV above the ground state. A detailed analysis of the molecular orbitals reveals the near degeneracy of the bilayer or icosahedral structures is rooted in the stabilization by p- or d-like cluster orbitals. The importance of low-lying spin states in controlling the electronic and magnetic properties of the cluster is highlighted.

No abstract

In this paper, the history, present status, and future of density-functional theory (DFT) is informally reviewed and discussed by 70 workers in the field, including molecular scientists, materials scientists, method...