C. Barbieri

This paper presents the problem of Molecular Beam Epitaxy and Reflection High-Energy Electron Diffraction with the help of a unified, modern MDA approach. Model-Driven Architecture (MDA) constitutes a modern and unusually efficient method of improving the process of generating software. It was created at the beginning of the twenty-first century by the Object Management Group as an element of Model-Driven Development, a highly promoted trend in software engineering. In MDA a viewpoint on a system is a technique for abstraction using a selected set of architectural concepts and structuring rules, in order to focus on particular concerns within a system. In MDA, system design begins with defining the problem domain. Next, at a highly abstract level independent of the system and programming platform a Platform-Independent Model (PIM) is constructed as well as a general system specification. This specification is created with the help of Unified Modeling Language. The real implementation of the system is performed through the transformation of PIM to Platform-Specific Model (PSM). The essence of Model-Driven Architecture is the replacement of the twentieth century approach to programming, calling that "everything is an object, to the modern "everything is a model". (C) 2011 Elsevier B.V. All rights reserved.

The Faddeev random-phase approximation is a Green’s function technique that makes use of Faddeev equations to couple the motion of a single electron to the two-particle–one-hole and two-hole–one-particle excitations. This method goes beyond the frequently used third-order algebraic diagrammatic construction method: all diagrams involving the exchange of phonons in the particle-hole and particle-particle channel are retained, but the phonons are now described at the level of the random-phase approximation, which includes ground-state correlations, rather than at the Tamm-Dancoff approximation level, where ground-state correlations are excluded. Previously applied to atoms, this paper presents results for small molecules at equilibrium geometry. © 2011 American Physical Society