High Level ab initio Calculations on Acetylene Dimer - A Prototype for Estimation of the Accuracy of the Benzene Dimer Stabilization Energy

Abstract

High level ab initio calculations (up to MP4/DZ + (2df,2p)) on acetylene dimer permit the evaluation of a highly accurate stabilization energy of the dimer (5.9 kJ/mol) and hence serves as a test case for the error limit for lower level calculations. This error limit was employed to estimate the stabilization energy and enthalpy in the benzene dimer calculation. From this the theoretical value of formation enthalpy at 0 K (11.3 kJ/mol) is obtained which is larger than the corresponding experimental value (6.7 ± 2.1 kJ/mol).