--- trunk/OOPSE/forceFields/DUFF.frc	2003/08/12 18:15:06	687
+++ trunk/OOPSE/forceFields/DUFF.frc	2003/11/25 15:44:32	875
@@ -1,6 +1,10 @@
 ! This is the forcefield file for the Dipolar Unified-atom Force Field (DUFF).
-! the sections are divided into AtomTypes, BondTypes, BendTypes,
+!
+! The sections are divided into AtomTypes, BondTypes, BendTypes,
 ! and TorsionTypes.
+!
+! Many parameters (but not all) are derived from the TRAPPE force field
+! of Siepmann's group.
 
 #AtomTypes
 !Atom		isDipole	isSSD	mass		LJ epsilon ( kcal/mol)		LJ sigma (Angstroms)	Dipole Moment (Debye)	w0	v0 (kcal/mol)	v0p (kcal/mol)	rl (Angstroms)	ru (Angstroms)	rlp (Angstroms)	rup (Angstroms)
@@ -11,12 +15,12 @@ TB1		0		0	57.375		0.0866				4.0
 CH		0		0	13.02		0.0189				4.68
 SSD		1		1	18.03		0.152				3.051			2.35	0.07715	3.7284	3.7284	2.75	3.35	2.75	4.0
 HEAD		1		0	196		0.185				5.75			20.6
-TB1		0		0	57.375		0.0866				4.0
-TE1		0		0	65.0		0.185				4.0
-TB2		0		0	57.375		0.0866				6.0
-TE2		0		0	65.0		0.185				6.0
-TB3		0		0	57.375		0.0866				8.0
-TE3		0		0	65.0		0.185				8.0
+TB1		0		0	14.03		0.0866				4.0
+TE1		0		0	15.04		0.185				4.0
+TB2		0		0	21.05		0.25				6.0
+TE2		0		0	22.56		0.5				6.0
+TB3		0		0	28.06		0.5				8.0
+TE3		0		0	30.08		0.75				8.0
 
 #BondTypes
 !Atom1	Atom2	type		distance	k0 (kcal/mol)
@@ -43,8 +47,12 @@ TB3	TE3	fixed		3.12		260
 
 
 #BendTypes
-!Atom1	Atom2	Atom3	type		k1	k2	k3	theta_0 ( k1 -> kcal/mol/degrees^2; theta_0 ->degrees )
-!V_bend = k1 * ( th - th0 )^2 + k2 * ( th - th0 ) + k3
+!Atom1	Atom2	Atom3	type		k1	k2	k3	theta_0 
+!
+! Units require ( k1 -> kcal/mol/degrees^2; theta_0 ->degrees )
+! consistent with the functional form:
+!
+!      V_bend = k1 * ( th - th0 )^2 + k2 * ( th - th0 ) + k3
 
 
 GHOST	HEAD	CH2	quadratic	0.00176972	0.0	0.0	129.783