Conformational analysis of n-alkanes using density functional theory. Comparison with ab initio calculations

Relative conformational energies of n-butane, n-pentane and n-hexane were calculated by the DFT method (Beckeʹs exchange and Lee, Yang and Parrʹs correlation functionals) with the 6-31G∗ basis set. The calculated energies were compared with experimental values and ab initio calculations. The DFT relative conformational energies agree better with the MP4 energies and experimental values than the HF energies.