Adsorption of guanine on Ge(100) was investigated using scanning tunneling microscopy (STM) and density functional theory (DFT) calculations. Guanine appears dark in STM images, indicating that its adsorption occurs through N-H dissociation. DFT calculations revealed that "N(1)-H dissociation through an O dative bonded structure" is the most favorable configuration.

We contend that the dependence of traditional density functional theory (DFT) on the one-electron density alone is both its strength and its weakness. We argue that progress beyond Kohn–Sham DFT involves the introduction of two-electron information and present intracules as a natural and concise source of this. We define special cases called the Jand K-intracules and discuss these in the contex...

The Hohenberg-Kohn theorem of the density functional theory ~DFT! is extended by modifying the Levy constrained-search formulation. The theorem allows us to choose arbitrary physical quantities as basic variables which determine the ground-state properties of the system. Moreover, the theorem establishes a minimum principle with respect to variations in chosen basic variables as well as with re...

The adsorption, diffusion and desorption of chlorine on and from stoichiometric, reduced and partially reduced (defective) rutile TiO2{110} are investigated using ab initio density functional theory (DFT) calculations. Theoretical results are compared with experimental investigations, and microkinetic simulations based on DFT values are then used to verify the diffusion mechanisms assumed in th...

Coinage metal cyanides (MCN) form photoluminescent 1D coordination polymers. The decoration of these chains with amine and phosphine ligands shifts the wavelength for photoluminescence into the visible region. Density-functional theory (DFT) and time-dependent DFT (TD-DFT) calculations of zigzag and helical models of decorated chains are used to show that the transitions that contribute to the ...

Density functional theory (DFT) is an incredible success story. The low computational cost, combined with useful (but not yet chemical) accuracy, has made DFT a standard technique in most branches of chemistry and materials science. Electronic structure problems in a dazzling variety of fields are currently being tackled. However, DFT has many limitations in its present form: too many approxima...

The structure of fluids confined by planar walls is studied using density functional theory. The density functional used is a generalized form of the hypernetted chain (HNC) functional which contains a term third order in the density. This term is chosen to ensure that the modified density functional gives the correct bulk pressure. The proposed density functional applied to a Lennard-Jones...

Based on classical density functional theory (DFT), we investigate the demixing phase transition of a two-dimensional, binary Heisenberg fluid mixture. The particles in the mixture are modeled as Gaussian soft spheres, where one component is characterized by an additional classical spin-spin interaction of Heisenberg type. Within the DFT we treat the particle interactions using a mean-field app...

We propose a nonlocal kinetic energy density functional KEDF for semiconductors based on the expected asymptotic behavior of its susceptibility function. The KEDF’s kernel depends on both the electron density and the reduced density gradient, with an internal parameter formally related to the material’s static dielectric constant. We determine the accuracy of the KEDF within orbital-free densit...

Density functional theory (DFT) provides a formally exact framework for quantum embedding. The appearance of nonadditive kinetic energy contributions in this context poses significant challenges, but using optimized effective potential (OEP) methods, various groups have devised DFT-in-DFT methods that are equivalent to Kohn-Sham (KS) theory on the whole system. This being the case, we note that...