Synopsis The inductive contribution to the retarded interatomic potential energy of two atoms in degenerate ground states is calculated up to all multipole orders on the basis of quantum electrodynamics. The result, which is found to have nonretarded character, is written in such a way as to show the induction effects brought about in each of the atoms by the electrostatic and magnetostatic fie...

We use recent theoretical advances to develop a functional form for interatomic forces in bulk silicon. The theoretical results underlying the model include an analysis of elastic properties for the diamond and graphitic structures and inversions of ab initio cohesive energy curves. The interaction model includes two-body and three-body terms which depend on the local atomic environment through...

We studied the line shape of Rb D1 and D2 resonance lines in the presence of 1–10 amg of several gases: He, He, N 2, and Xe. We found that the line cores are well described by the asymmetric line shape expected for a van der Waals interatomic potential. The width and shift of the lines is proportional to the density of the foreign gas with high degree of accuracy, while the asymmetry is indepen...

We present a number of new, exact scalar field cosmologies where the potential consists of two or more exponential terms. Such potentials are motivated by supergravity or superstring models formulated in higher dimensional spacetimes that have been compactified to (3+1)-dimensions. We have found solutions in both curved and flat Robertson Walker spacetimes. These models have a diverse range of ...

P. Keblinski, M. Z. Bazant, R. K. Dash, and M. M. Treacy Materials Science and Engineering Department, Rensselaer Polytechnic Institute, Troy, New York 12180-3590 Department of Mathematics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 NEC Research Institute, Inc., Princeton, New Jersey 08540 ~Received 26 March 2002; revised manuscript received 13 June 2002; published 9 ...

A model for Al(Si)Mn quasicrystals is proposed. It is characterized by pure quasiperiodic long range order with icosahedral symmetry. The density and concentrations fit to the experimental values. The interatomic distances are compatible with crystallographic data and compare well to the related 03B1 phase. A large number of icosahedral clusters (Mackay icosahedra) are present in the model. J. ...