A Density-Based Basis-Set Correction for Wave Function Theory

<div><div><div><p>We report a universal density-based basis-set incom-<br>pleteness correction that can be applied to any wave<br>function method. The present correction, which ap-<br>propriately vanishes in the complete basis set (CBS)<br>limit, relies on short-range correlation density func-<br>tionals (with multi-determinant reference) from range-<br>separated density-functional theory (RS-DFT) to esti-<br>mate the basis-set incompleteness error. Contrary to<br>conventional RS-DFT schemes which require an ad hoc<br>range-separation parameter μ, the key ingredient here<br>is a range-separation function μ(r) that automatically<br>adapts to the spatial non-homogeneity of the basis-set<br>incompleteness error. As illustrative examples, we show how this density-based correction allows us to obtain CCSD(T) atomization and correlation energies near the CBS limit for the G2 set of molecules with compact Gaussian basis sets.</p></div></div></div>