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Fradera i LlinÃ s, Xavier
Duran i Portas, Miquel Mestres i LÃ³pez, Jordi 

The contributions of the correlated and uncorrelated components of the electronpair density to atomic and molecular intracule I(r) and extracule E(R) densities and its Laplacian functions âˆ‡2I(r) and âˆ‡2E(R) are analyzed at the HartreeFock (HF) and configuration interaction (CI) levels of theory. The topologies of the uncorrelated components of these functions can be rationalized in terms of the corresponding oneelectron densities. In contrast, by analyzing the correlated components of I(r) and E(R), namely, IC(r) and EC(R), the effect of electron Fermi and Coulomb correlation can be assessed at the HF and CI levels of theory. Moreover, the contribution of Coulomb correlation can be isolated by means of difference maps between IC(r) and EC(R) distributions calculated at the two levels of theory. As application examples, the He, Ne, and Ar atomic series, the C22, N2, O2+2 molecular series, and the C2H4 molecule have been investigated. For these atoms and molecules, it is found that Fermi correlation accounts for the main characteristics of IC(r) and EC(R), with Coulomb correlation increasing slightly the locality of these functions at the CI level of theory. Furthermore, IC(r), EC(R), and the associated Laplacian functions, reveal the shortranged nature and high isotropy of Fermi and Coulomb correlation in atoms and molecules  
http://hdl.handle.net/2072/101679  
eng  
American Institute of Physics  
Tots els drets reservats  
ArgÃ³
Compostos orgÃ nics FermiCoulomb, Correlacions de Funcional de densitat, Teoria del HartreeFock, Teoria de Heli Laplace, Transformacions de NeÃ³ Compostos de nitrogen Argon Density functionals FermiCoulomb correlations HartreeFock theory Helium Laplace tranformations Neon Nitrogen compounds Organic compounds 

The mapping of the local contributions of Fermi and Coulomb correlation into intracule and extracule density distributions  
info:eurepo/semantics/article  
Recercat 