QSPR modeling of alkanes properties based on graph of atomic orbitals

Graphs of atomic orbitals (GAOs) have been used to represent molecular structures of alkanes. The GAO is attempted at taking into account the structures of atoms for QSPR analyses. As a method of modeling of alkanes' properties (molar heat capacity at 300 K, normal boiling points, density at 25 degreesC, refractive index at 25 degreesC, standard Gibbs energy of formation in the gas phase at 300 K, and vaporization enthalpy at 300 K), optimization of correlation weights of local graph invariants (OCWLGI) has been used. These optimization procedures based on the labeled hydrogen-filled graph (LHFGs) and the GAOs have been carried out. It has been shown that OCWLGI based on the GAOs gives models of alkanes properties under consideration which are better than these based on the LHFGs. (C) 2003 Published by Elsevier B.V.