Sensitivity Analysis and Uncertainty Calculation for Dispersion Corrected Density Functional Theory

The precision of binding energies and distances computed with dispersion-corrected density functional theory (DFT- D) is investigated by propagation of uncertainties, yielding relative uncertainties of several percent. Sensitivity analysis is used to calculate the geometry-dependent relative importance of each input parameter for the dispersion correction. While DFT-Ds are exact at asymptotically large distances, their damping functions are shown to play a significant role in binding geometries. This is demonstrated in detail for the interlayer binding of graphite. The techniques presented allow practitioners to quickly compute error bars and to get an a posteriori estimate about the transferability of their results. They can also aid the development of future dispersion corrections. (C) 2011 Wiley Periodicals, Inc. J Comput Chem 32: 1424-1430, 2011