Quantum Monte Carlo vs. Density Functional Methods for the Prediction of Relative Energies of Small Si-C Clusters

Abstract

In the present paper, we assess the accuracy of popular and widely used approaches based on density functional theory by relating them to the most accurate at present quantum Monte Carlo calculations. As the test case, we consider the relative stability of small SinCm isomers. We find out that none of the studied DFT approaches employing local, semilocal, or even hybrid functionals are able to predict correctly the relative stability of the isomers.