Rovibrational spectroscopic constant of tetrahydrofuran (THF) dimer have been calculated starting from three potential energy curves, each one obtained in a different way: (i) by ab initio calculations at MP2/aug-cc-pVDZ level; (ii) using Lennard-Jones liquid parameters available in the literature, and (iii) from the pair obtained through Monte Carlo Simulation of liquid THF. The comparison among these results allowed the characterization of many solvent effect contributions.