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 wavefunction 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 toconventional RS-DFT schemes which require an ad hocrange-separation parameter μ, the key ingredient hereis a range-separation function μ(r) that automaticallyadapts to the spatial non-homogeneity of the basis-setincompleteness 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.