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

We report a universal density-based basis-set incom-
pleteness correction that can be applied to any wave
function method. The present correction, which ap-
propriately vanishes in the complete basis set (CBS)
limit, relies on short-range correlation density func-
tionals (with multi-determinant reference) from range-
separated density-functional theory (RS-DFT) to esti-
mate the basis-set incompleteness error. Contrary to
conventional RS-DFT schemes which require an ad hoc
range-separation parameter μ, the key ingredient here
is a range-separation function μ(r) that automatically
adapts to the spatial non-homogeneity of the basis-set
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.