Table 2.

Average Bond Lengths (Å) and the Root-Mean-Square Deviations (RMSD) for the Carbon–Carbon Bond from Molecular Dynamic Simulations of Ethane at 300 K^a

	HF		PHO		Tet		NR
	average	RMSD	average	RMSD	average	RMSD	average	RMSD
def2-SVP	1.531	0.036	1.548	0.026	1.644	0.078	1.605	0.051
6–31G(d)	1.534	0.012	1.548	0.029	1.632	0.051	1.604	0.064
6–311+G(d,p)	1.531	0.023	1.544	0.028	1.615	0.059	1.593	0.079
def2-TZVP	1.528	0.038	1.544	0.028	1.616	0.59	1.591	0.067
	DFT		PHO		Tet		NR
	average	RMSD	average	RMSD	average	RMSD	average	RMSD
def2-SVP	1.532	0.016	1.546	0.030	1.640	0.074	1.612	0.072
6–31G(d)	1.536	0.023	1.546	0.023	1.637	0.073	1.604	0.065
6–311+G(d,p)	1.537	0.023	1.543	0.024	1.621	0.069	1.585	0.049
def2-TZVP	1.532	0.017	1.540	0.024	1.616	0.060	1.591	0.054

^aCalculations were performed with the Hartree–Fock theory (HF) and density functional theory (DFT) for the full system, and QM/MM potentials with the hybrid project hybrid orbital (PHO) model, the tetrahedral restraining potential only (Tet) and without any molecular mechanics restraints (NR).