. 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 16.

Valine Dipeptide, Energy of the Conformers, RMS Deviations in ϕ, ψ, χ₁ from the Ab Initio Data.

Conformer	Ab initio ^a	PFF	OPLS-AA/L 2^b	OPLS-AA/L 3^b
1	0.00	0.00/3.9	0.06/6.2	−0.20/6.5
2	0.35	0.36/2.1	0.24/3.2	0.36/3.3
3	0.69	0.67/7.6	0.74/12.8	0.87/12.9
RMS error^c	—	0.01/5.1	0.08/8.4	0.16/8.6

Energies in kcal/mol, angles in degrees.

LMP2 cc-pVTZ(-f)//HF6-31G**, ref. 1.

Positions of the minima shifted uniformly to achieve the lowest RMS deviation from the ab initio results.