Improving the Accuracy of Low Level Density Functional Theory Calculation for Absorption Energies: The Least Squares Support Vector Machine

Least squares support vector machines (LS-SVM) was introduced to improve the calculation accuracy of low level density functional theory. As a demonstration, this combined low level quantum mechanical calculation with LS-SVM correction approach has been applied to evaluate the absorption energies of 160 organic molecules. After LS-SVM correction, the RMS deviations of the calculated absorption energies reduce from 0.95 to 0.16 eV for B3LYP/STO-3G methods. And, this LS-SVM/B3LYP/STO-3G is a excellent method to predict absorption energies and can be used as an alternative to experimental measurements and high-accurate quantum chemical calculations to obtain the value of absorption energies reliably and efficiently.