The implementation of Ψ λ using FCI allows us to compute e λ c (r), from which the λ-averaged e c (r) is obtained (see Eq. 22). However, calculating e λ c (r) across a full λ grid between 0 and 1 requires ∼ 20 FCI calculations for each value considered λ, as discussed above. To test whether this computational cost can be reduced while maintaining accuracy, we employ the Padé[1/1] interpolation scheme (see Ref.