Quantum Mechanical Calculations for Benzene Dimer Energies: Present Problems and Future Challenges.

Factors influencing quantum mechanical calculations of nonbonded interactions between organic molecules are still imperfectly understood. Much effort has gone into efforts to calculate the structures and binding energies of stable benzene dimers. However, little experimental evidence is available for comparison with theoretical results. As a benchmark for assessing the reliability and accuracy of such calculations, the benzene crystal structure seems a more suitable target than the elusive dimer structures.