Wavefunction analysis

This chapter discusses a number of approaches towards finding this Grail—the classic chemical concepts contained within the wavefunction. In the next section, we present the mathematical derivations of a number of the current methods for analysis of the wavefunction. Population analysis is the term frequently applied to this procedure. Population analysis attempts to determine the number of electrons associated with a particular atom or orbital. In the third section, we present a few examples of the application of the various methods applied to understanding the chemistry of some compounds. The methods are contrasted and their advantages and disadvantages delineated. The fourth section provides some guidelines for using the methods, and in the last section we contemplate the future of wavefunction analysis. 

The charge attributed to an atom A within a molecule, defined as = Za — where Za is the atomic number of atom A and A is the electron density (see Atoms in Molecules) assigned to A. The calculation of q depends on the partitioning of the electron density. In the framework of Mulliken population analysis (see Electronic Wavefunctions Analysis), cja is related to the gross atomic population H q, where q is the gross... 

Electronic Wavefunctions Analysis Transition Metal Che> mistry. 

The importance of hyperconjugative effects on A sx was rejected on the basis of various GVB approaches and Mulliken population analyses (see Electronic Wavefunctions Analysis) for methylcarbene. It was concluded that it is not the singlet state stabilization by the methyl group but rather the triplet state destabilization which results in a smaller singlet-triplet separation with respect to methylene. The GVB Mulliken population analyses show that the hybridizations of the a orbitals are almost identical in the singlet states of methylene and methylcarbene. For the triplet states, however, Mulliken population analyses indicate a decrease in p character when... 

AMI Basis Sets Correlation Consistent Sets Complete Active Space Self-consistent Field (CASSCF) Second-order Perturbation Theory (CASPT2) Configuration Interaction Coupled-cluster Theory Density Functional Theory (DFT), Hartree-Fock (HF) and the Self-consistent Field Diradicals Electronic Wavefunctions Analysis G2 Theory M0ller-Plesset Perturbation Theory Natural Bond Orbital Methods Spin Contamination. 

AMBER A Program for Simulation of Biological and Organic Molecules Atoms in Molecules Charge Flux Electronic Wavefunctions Analysis Electrostatic Potentials Chemical Applications Free Energy Changes in Solution Natural Bond Orbital Methods Natural Orbitals. 

Basis Sets Correlation Consistent Sets Benchmark Studies on Small Molecules Configuration Interaction Electronic Wavefunctions Analysis Natural Orbitals. 

Configuration Interaction Core-Valence Correlation Effects Dynamic Properties Electron-Molecule Scattering Electronic Wavefunctions Analysis Green s Function Ionization Potentials in Semiempirical MO Theory M0l-ler-Plesset Perturbation Theory Pseudospectral Methods in Ab Initio Quantum Chemistry Spectroscopy Computational Methods Time Correlation Functions. 

Atoms in Molecules Electron Transfer Calculations Electronic Wavefunctions Analysis Hyperconjugation Intermolecular Interactions by Perturbation Theory Localized MO SCF Methods Natural Orbitals NMR Chemical Shift Computation Ab Initio Rotational Barriers Barrier Origins Valence Bond Curve Crossing Models. 

Continuum Solvation Electronegativity and the Periodic Table Electronic Wavefunctions Analysis Free Energy Changes in Solution G2 Theory Natural Bond Orbital Methods Rotational Barriers Barrier Origins Self-consistent Reaction Field Methods. 

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