. Author manuscript; available in PMC: 2014 Mar 24.

Published in final edited form as: J Comput Chem. 2002 Dec;23(16):1515–1531. doi: 10.1002/jcc.10125

Table 6.

Alanine Dipeptide, Energy of the Conformers, RMS Deviations in ϕ, ψ from the Ab Initio Data.

Conformer	Ab initio ^a	PFF	OPLS-AA/L^b
C7_eq	0.00	−0.23/9.3	−0.11/9.1
C5	0.95	0.77/1.2	0.82/4.5
C7_ax	2.67	2.48/6.5	2.46/0.5
β ₂	2.75	—	—
α _L	4.31	—	—
α ′	5.51	6.11/8.6	5.97/8.0
RMS error^c	—	0.35/7.1	0.27/6.5

Energies in kcal/mol, angles in degrees.

LMP2 cc-pVTZ(-f)//HF6-31G**, ref. 21.

Ref. 1.

Positions of the minima shifted uniformly to achieve the lowest RMS deviation from the ab initio results. The RMS computed for the C7, C5, and α′ minima only.