François Colonna

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By splitting the Coulomb interaction into long-range and short-range components, we decompose the energy of a quantum electronic system into long-range and short-range contributions. We show that the long-range part of the energy can be efficiently calculated by traditional wave function methods, while the short-range part can be handled by a density(More)
We propose approximations which go beyond the local-density approximation for the short-range exchange and correlation density functionals appearing in a multideterminantal extension of the Kohn-Sham scheme. A first approximation consists of defining locally the range of the interaction in the correlation functional. Another approximation, more(More)
Using recent calculations we review some well-known aspects of density functional theory: the Hohenberg–Kohn theorems, the Kohn–Sham method, the adiabatic connection, and the approximations of local nature. Emphasis is put upon using model Hamiltonians, of which the noninteracting or the physical ones are just particular cases. The model Hamiltonians allow(More)
Careful calculations are performed to obtain the radial density–density response function for the He and the Be series. This is also done along the adiabatic connection of the density functional theory ͑as the system evolves from the real, physical system to the Kohn–Sham one͒. In this process the electron density is kept constant, while the strength of the(More)
Switching on the electron–electron interaction connects the Kohn–Sham to the physical system. The correlation energy, the only unknown energy component in this process, is determined at fixed density, using a technique based on the Lieb Legendre transform definition of the universal density functional. Results are shown for this adiabatic coupling process(More)
Preamble This document is a working document, it may never be published in a scientific journal. It is aimed at starting a discussion on the interest of the kind of programming method explained below. Any comments or corrections are welcomed can be written in color in this document and sent back to me. Abstract We propose some slight additions to O-O(More)
Preamble This document is a working document, it may never be published in a scientific journal. It is aimed at starting a discussion on the interest of the kind of programming method explained below. Any comments or corrections are welcomed can be written in color in this document and sent back to me. Abstract We propose some slight additions to O-O(More)
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