Topological Chemograph Analysis Theory As a Promising Approach to Simulation Modeling of Quantum-Mechanical Properties of Molecules. Part II: Quantum-Chemical Interpretations of Chemograph Theory

Abstract—

An interpretation of the problem-oriented theory developed is given from different perspectives of quantum chemistry. It is shown that the results obtained within the developed formalism correspond to the solution of the single-electron Schrödinger equation on molecular fragments, to the additive scheme of electron density calculation in the density functional theory, and to the correction of the integrals of overlapping in the molecular orbital theory. The algorithms based on the developed formalism were tested on a sample of 134 thousand molecules, for which the highest occupied molecular orbital (HOMO) energy, the lowest unoccupied molecular orbital (LUMO) energy, the HOMO–LUMO gap energy, the rotational constants, etc., were calculated by the B3LYP/6-31G(2df,p) method of quantum-mechanical calculations. The cross-validation testing of linear and nonlinear models has resulted in rank correlations between calculated and experimental values within a range of 0.67–0.85. In this case, the speed of calculations by the developed algorithms is higher than for quantum-mechanical calculations by eight orders of magnitude. The developed algorithms can be used for large-scale screenings of molecules when solving the problems of molecular pharmacology and materials science.