--- trunk/OOPSE/forceFields/DUFF.frc	2003/06/25 21:11:42	566
+++ trunk/OOPSE/forceFields/DUFF.frc	2004/01/19 18:51:39	963
@@ -1,50 +1,58 @@
-! This is the forcefield file for the TraPPE force field.
-! the sections are divided into AtomTypes, BondTypes, BendTypes,
+! This is the forcefield file for the Dipolar Unified-atom Force Field (DUFF).
+!
+! 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)
+!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)
 
 CH4		0		0	16.05		0.279				3.73
 CH3		0		0	15.04		0.185				3.75
 CH2		0		0	14.03		0.0866				3.95
 CH		0		0	13.02		0.0189				4.68
-SSD		1		1	18.03		0.152				3.051			2.35	0.07715	3.7284
+SSD		1		1	18.015		0.152				3.035			2.42	0.07715	3.9	3.9	2.4	3.8	2.75	3.35
 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)
 
-HEAD	CH3	harmonic	2.75		260
-HEAD	CH2	harmonic	2.75		260
-HEAD	CH	harmonic	2.75		260
-HEAD    TB1	harmonic	2.76		260
-HEAD	TB2	harmonic	3.20		260
-HEAD	TB3	harmonic	3.63		260
-CH3	CH3	harmonic	1.526		260
-CH3	CH2	harmonic	1.526		260
-CH3	CH	harmonic	1.526		260
-CH2	CH2	harmonic	1.526		260
-CH2	CH	harmonic	1.526		260
-CH	CH	harmonic	1.526		260
-TB1	TB1	harmonic	1.526		260
-TB2	TB2	harmonic	2.34		260
-TB3	TB3	harmonic	3.12		260
-TB1	TE1	harmonic	1.526		260
-TB2	TE2	harmonic	2.34		260
-TB3	TE3	harmonic	3.12		260
+HEAD	CH3	fixed		2.75		260
+HEAD	CH2	fixed		2.75		260
+HEAD	CH	fixed		2.75		260
+HEAD    TB1	fixed		2.76		260
+HEAD	TB2	fixed		3.20		260
+HEAD	TB3	fixed		3.63		260
+CH3	CH3	fixed		1.526		260
+CH3	CH2	fixed		1.526		260
+CH3	CH	fixed		1.526		260
+CH2	CH2	fixed		1.526		260
+CH2	CH	fixed		1.526		260
+CH	CH	fixed		1.526		260
+TB1	TB1	fixed		1.526		260
+TB2	TB2	fixed		2.34		260
+TB3	TB3	fixed		3.12		260
+TB1	TE1	fixed		1.526		260
+TB2	TE2	fixed		2.34		260
+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