--- trunk/OOPSE-3.0/forceFields/DUFF2.frc	2005/03/08 21:05:18	2083
+++ trunk/OOPSE-3.0/forceFields/DUFF2.frc	2005/03/21 22:34:40	2130
@@ -92,31 +92,60 @@ begin ElectrostaticAtomTypes
 Kr	  0.32590340268		3.83	              
 end LennardJonesAtomTypes
 
-begin ElectrostaticAtomTypes
-//only support up tp quadrupole.
-//Below are possible format
-//name 0 charge
-//name 1 charge dipole [phi, theta, psi]
-//name 2 charge dipole Qxx Qyy Qzz [phi, theta, psi]
-//note: [phi, theta, psi] is optional, by default, they are [0, 0, 0]
-SSD_E   	1	0.0	2.42
-SSD_RF  	1	0.0	2.48
-SSD     	1	0.0	2.35
-SSD1		1	0.0	2.35
-O_TIP3P 	0	-0.834
-O_SPCE  	0	-0.8476
-O_SPC   	0	-0.82
-H_TIP3P		0	0.417
-H_TIP4P		0	0.520
-H_TIP5P		0	0.241
-H_SPCE		0	0.4238
-H_SPC		0	0.42
-EP_TIP4P	0	-1.040
-EP_TIP5P	0	-0.241
-HEAD		0	20.6
-Cl              0       -1.0
-end ElectrostaticAtomTypes
+begin ChargeAtomTypes
+// Name charge
+O_TIP3P  -0.834
+O_SPCE   -0.8476
+O_SPC    -0.82
+H_TIP3P   0.417
+H_TIP4P   0.520
+H_TIP5P   0.241
+H_SPCE    0.4238
+H_SPC     0.42
+EP_TIP4P -1.040
+EP_TIP5P -0.241
+Cl	 -1.0
+end ChargeAtomTypes
 
+begin MultipoleAtomTypes
+// OOPSE currently only supports charge-charge, charge-dipole, 
+// dipole-dipole, and charge-quadrupole interactions.
+// Dipoles may be either traditional point-dipoles or split-dipoles.
+// possible formats for a multipolar atom type are:
+//
+// Point-dipoles:
+// name d phi theta psi dipole_moment
+//
+// Split-dipoles:
+// name s phi theta psi dipole_moment splitdipole_distance
+//
+// Point-Quadrupoles:
+// name q phi theta psi Qxx Qyy Qzz
+//
+// Atoms with both dipole and quadrupole moments:
+// name dq phi theta psi dipole_moment Qxx Qyy Qzz
+//
+// Atoms with both split dipoles and quadrupole moments:
+// name sq phi theta psi dipole_moment splitdipole_distance Qxx Qyy Qzz
+//
+// Euler angles are given in zxz convention in units of degrees.
+//
+// Charges are given in units of electrons.
+//
+// Dipoles are given in units of Debyes.
+//
+// Split dipole distances are given in units of Angstroms.
+//  
+// Quadrupole moments are given in units of 10^-26 esu cm^2 (also known as an
+//                                                           esu centi-barn)
+//
+SSD_E   dq       0.0     0.0     0.0     2.42  -1.682  1.762  -0.08
+SSD_RF  dq       0.0     0.0     0.0     2.48  -1.682  1.762  -0.08
+SSD     dq       0.0     0.0     0.0     2.35  -1.682  1.762  -0.08
+SSD1    dq       0.0     0.0     0.0     2.35  -1.682  1.762  -0.08
+//HDP     s       0.0     0.0     0.0     20.6    4.63
+end MultipoleAtomTypes
+
 begin StickyAtomTypes
 //name w0	v0 (kcal/mol)   v0p	rl (Ang)  ru	rlp	rup
 SSD_E	0.07715	3.90		3.90	2.40	  3.80	2.75	3.35