An alternative approach is SAPT(DFT), which uses coupled Kohn-Sham response theory to obtain E disp and is also found to agree well with the best wave function benchmarks. By exploiting density fitting, the computational scaling of SAPT(DFT) calculations with hybrid XC functionals can be reduced to O(N 5 ), albeit with a much larger prefactor as compared to fifthorder methods such as MP2. SAPT(DFT) calculations up to 200 atoms have been demonstrated, but few systematic benchmarks are available.