About amber parameters

[William Wei <william ^at^ phm.utoronto.ca>]

Hi, Dear CCL'ers,
 I am a new user of amber. I have problems with developing parameters.
 Here is my steps:
 1.  Create new residue, import two residues from amber, connect them,
 and draw other part of the new residue.
 2.  Save the new residue in PDB file. Open it with sybyl, and the bonds
 I drawn between residues(amber) were lost.  I drew it, and use mopac to
 caculate the charge.
 3.  Construct the charge, atoms type in xleap.
 4.  Construct the force parameters for the new residues.
 After these steps, I load the new residue OFF file and new force
 parameters, check the unit, it is okay. Then my problem was coming:
 while I ran xleap, load my new residue,  xleap can not recognize my new
 atoms tpye.  And while I save the residue to pdb file in leap, The sybyl
 can not draw it well.  Does anyone have developed parameters? I really
 appreciate your help. Or give me some information of amber .OFF file's
 type.
 William.