Vacuum energies are computed in light-cone field theories to obtain effective potentials which determine vacuum condensate. Quantization surfaces interpolating between the light-like surface and the usual spatial one are useful to define the vacuum energies unambiguously. The GrossNeveu, SU(N) Thirring, and O(N) vector models are worked out in the large N limit. The vacuum energies are found to...

Atomic hydrogen adsorption energies on bimetallic overlayer systems have been determined by periodic density functional theory calculations within the generalized gradient approximation. On the pseudomorphic Pd/Cu(111) surface, both the substrate interaction and the lattice compression of the Pd overlayer lead to smaller hydrogen binding energies. For pseudomorphic Cu/Pd(111), on the hand, the ...

A theoretical model of molecule-surface scattering is developed which includes energy and momentum transfers between the surface and projectile for both translational and rotational motions and internal mode excitation for the projectile molecule. The translation and rotation motions are treated in the classical limit, while a quantum treatment for internal vibrational mode excitation is used. ...

A Ginzburg–Landau type functional for a multi–phase system involving a diffuse interface description of the phase boundaries is presented with the following calibration property: Prescribed surface energies (possibly anisotropic) of the phase transitions are correctly recovered in the sense of a Γ–limit as the thickness of the diffuse interfaces converges to zero. Possible applications are grai...

The free energy of a (1×1)-surface, with no relaxation and no adsorption, is calculated using a bond-breaking mode in which the potential energy of the crystal is treated as the sum of the energy of the bonds connecting pair-wise atoms. Based on a purely geometrical model, the number of broken bonds or dangling bonds per atom is calculated on the surface of the crystal when an atomically flat p...

The efficient evaluation of electrostatic energies of macromolecules in aqueous solutions is useful for many problems in theoretical structural biology. A continuum method based on the generalized Born (GB) approximation is implemented here. It is shown that the choice of the dielectric discontinuity surface is critical for obtaining correct electrostatic energies of molecules in solution. In a...

Surface energies of Si(001), (110), (111), and (113) surfaces with different reconstructions are calculated systematically using first-principles total-energy method. In order to quantitatively compare their relative stability, the surface energies of different surface orientations and their respective theoretical bulk atom energies are determined simultaneously by linear fitting slab supercell...

Recent high precision experimental data for heavy-ion fusion reactions at subbarrier energies systematically show that a surprisingly large surface diffuseness parameter for a Woods-Saxon potential is required in order to fit the data. We point out that experimental data for quasi-elastic scattering at backward angles also favor a similar large value of surface diffuseness parameter. Consequent...

We have computed absorption and emission energies of silicon nanocrystals as a function of size and of surface passivants, using both density functional theory and quantum Monte Carlo calculations. We have found that the ionic rearrangements and electronic relaxations occurring upon absorption and emission are extremely sensitive to surface chemistry. In particular, nanoclusters with similar si...

The structure and surface energies of the cleaved, reconstructed, and fully hydroxylated (001) alpha-quartz surface of various thicknesses are investigated with periodic density functional theory (DFT). The properties of the cleaved and hydroxylated surface are reproduced with a slab thickness of 18 atomic layers, while a thicker 27-layer slab is necessary for the reconstructed surface. The per...