Table I.

Comparison between the absolute free energy for alanine dipeptide estimate using two different fragmentation schemes. Our “standard” three-fragment decomposition (Ace, Ala, Nme) is compared to a two-fragment grouping (Ace-Ala, Nme). The table gives free energy values in kcal/mole, as well as two standard deviations (in parentheses) based on 20 independent calculations.

Alanine dipeptide free energy terms from Eq. (24) and Eq. (25)
Three Fragments		Two Fragments
Term	Estimate [kcal/mol]	Term	Estimate [kcal/mol]
FAce	14.783(0.003)	FAce-Ala	47.311(0.027)
FAla	33.326(0.015)	FNme	16.574(0.003)
FNme	16.574(0.003)	ΔFAce—Ala→Nme	−0.792(0.002)
ΔFAce→Ala	−0.801(0.002)
ΔFAla→Nme	−0.499(0.007)
ΔFnonbonded	−0.285(0.008)
Fphys	63.098(0.015)	Fphys	63.093(0.028)