Intermolecular potential energy surface (IPS) for protein — protein has been examined using RHF, DFT-B3LYPand MP2 levels of theory with 6-31G, 6-31G* basis sets. A number of basis sets were used in order to evaluatethe basis set effects, at all three levels of theory, basis sets has significant effects on the calculated potentialenergy curves (including position, depth and width of the potentia...