weighted towards asymptotic regions of the molecule using a function w(r). The latter is taken to be 32 w(r) = 1, t(r) ≤ µ 0, t(r) > µ (9) where t(r) is Becke's orbital localization function. In the context of eq. 9, t(r) ensures that w(r) ≈ 0 in the region of localized orbitals. The parameter µ is determined self-consistently so that 32 ρ(r) w(r) dr = 1 .