Attractors, electron density analysis

Attractors, electron density analysis, 223 Bra. 55 Conical intersection. 364 Density matrix. 66. 229 ... 

Atoms In Molecules (AIM), 223 Attractors, electron density analysis, 223 Augmented Hessian, function optimization, 320... 

The analysis of the location of bond paths, of their trajectories and flie distribution of the electron density in species analyzed, especially if such a distribution is discussed on the basis of the laplacian of the electron density, are very useful tools to deepen the understanding of the nature of interactions. This is also important that the analysis of the molecular graphs is often in line with the results of other approaches. This is worth mentioning that the molecular graph may be treated as a source of information on the location of atomic attractors (positions of atoms) and on the location of bond paths corresponding to the preferable stabilizing interactions. 

The results of the N-Ol bond electronic structure, studied in the real space using topological analysis of ELF, will vary depending on the computational method used. At the DFT(B2PLYP)/aug-cc-pVTZ computational level, the N-Ol bonds in both conformers are described by two monosynaptic attractors, V(01) and V(N). Such ELF-topology is characteristic for the protocovalent bond. The core and valence attractors in the syn and anti conformer of the nitrous acid are shown in Fig. 19.3. Similar analysis, carried out using the B3LYP hybrid electron density... 

The topological analysis of the density and of the ELF funetion provides new information to understand the nature of the Si-0 bond. On the one hand, the atomic population and the bond ellipticities tell us that the SiO bond is partly ionic and also that there is no evidence for a partial double bond character. This latter point is confirmed by the analysis of the ELF function since there is only one attractor between the oxygen and silicon cores and that its basin population is always less than or equal to 2 electrons. Moreover, it appears more important to consider the oxygen than the silicon to discuss the bonding in silica. The Si-0 bond is found to belong to the electron shared interaction by the ELF analysis. 

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