Intracule-Extracule

3 Intracule-Extracule. - The properties of the electron intracule and one-electron densities of the ground state of harmonium were determined and expressed in terms of asymptotic expansions and Pade approximants. Topologies of both densities were investigated in detail. An attractor composed of a cage critical point and a (1,-1) critical sphere. 

Fradera et al. reported on the topological features of molecular intracule I and extracule densities E and their Laplacian distributions computed at the HF and CISD and interpret them in terms of VB structures. Within this framework 

The contributions of the correlated and uncorrelated components of the electron-pair density to atomic and molecular intracule I and extracule E densities and their Laplacian functions were analysed at the HF and Cl level. The correlated components of the / and E densities, and their associated Laplacian functions, reveal the short-ranged nature and high isotropy of Fermi and Coulomb correlation in atoms and molecules. In general, it has been found that the uncorrelated / and E have the same topological structure as the parent functions I and E functions. 

Fradera et analysed electron-pair interactions from intracule / and 

1 Organic. - Meng et al traced the intrinsic reaction coordinate of the reaction of triplet O with CS2 and analysed its stationary points. The topological analysis of p was employed to investigate the changes of chemical bonds in the reaction process. 

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Thakkar and his group have completed many careful studies of intracules, extracules, Coulomb holes, and related topics.145 These position-space results are complemented by Thakkar s many studies of momentum densities and related quantities. He also has a long-standing interest in electron and X-ray scattering.146 His current interests include the relationship147 between the aromaticity of heterocyclic compounds and their polarizabilities, and the prediction of push-pull molecules that have a large nonlinear optical response and are thus candidates for materials to be used in optical computers. 

A. J. Thakkar, Extracules, intracules, correlation holes, potentials, coefficients and all that, in Density Matrices and Density Functionals, R. M. Erdahl and V. H. Smith, Jr., eds. (Reidel, Dordrecht, Holland, 1987), pp. 553-581. 

J. Cioslowski and G. Liu, Fast evaluation of electron intracule and extracule densities on large grids of points, J. Chem. Phys. 105, 4151-4158 1996. 

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