To make an informed decision on the forcefield to use in the subsequent calculations, the interaction energies of eight molecules (acetaminophen, caffeine, carbamazepine, fluoxetine, ibuprofen, sulfamethoxazole, tris(2-chloroethyl) phosphate and triclosan), covering a relatively wide variety of chemical space, in two different zeolite frameworks (FAU and MOR) were validated against rev-vdW-DF2 /TZVP interaction energies, published by Fischer and Brauer . Additionally, the interaction energies of Carbamazepine in 11 zeolite frameworks were considered for validation. Three small molecule forcefields, GAFF2 , OPLS-AA and Sage OpenFF 2.0 , and three sets of Lennard-Jones parameters and atomic charges for the zeolite framework atoms SiZeo and OZeo , , were tested. The best agreement with the DFT interaction energies was obtained by combining the Sage OpenFF 2.0 for the molecules with the Lennard-Jones parameters and charges of Emami et al. for the zeolite frameworks (further information in the SI).