Quantum chemical variables in QSAR: A review
J.P. Hickey, Dora R. May Passino · OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information) · 1994
The integration of molecular orbital calculations with QSAR analyses has resulted in many ``theoretical`` indices. The authors will present a brief overview of these numerous quantum chemical parameters used in QSAR, as well as a small sampling of their applications (e.g., correlation of carcinogenicity with structure for PAHS, and MO calculations to predict toxicity of PCDDs and PCDFS). The quantum mechanical indices described here are compiled from many sources and are generally obtained from classical molecular mechanical methods, as well as from calculated molecular wavefunctions. The quality of the model or wave function and, consequently, of the indices depend entirely on the formalism and the level of approximation used. Because the molecular waveform is often described as a linear combination of atomic orbitals (LCAO), one can easily obtain some of the indices. These include the atomic charges, sigma and pi charges, frontier electron densities, E{sub HOMO}, and E{sub LUMA} and the superdelocalizability parameters. Parameter computation methods and appropriate software (and sources) will be highlighted.