[gmx-users] (no subject)

[Nikita Polyakov]

Hello all!
I'm trying to convert Amber dihedral constants to ffoplsaabon.itp.
I took opls_parm.dat from Amber7 force field and extact that line for 
try:
  
X -CK-CB-X    4    5.3        180.              2. 
  
Supposed dihedral is:
  
C2=-5.565
In that case probably C0 = -C2 = 5.565. So C1=C3=C4=C5=0
X      CA     C      X       3      5.565     0.00000   5.565 
    0.00000   0.00000   0.00000 
  
  
But in ffoplsaabon.itp for example:
CA     CA     C      N       3      4.60548   0.00000  -4.60548 
  0.00000   0.00000   0.00000 ; benzamide 
  
Could you explain difference or where I did mistake?
  
  
Nikita Polyakov, MSU student.