I tried to generate restraints of 3-METHYL-BETA-D-ASPARTIC ACID (PDB 3 letter code ACB, http://www.rcsb.org/pdb/ligand/ligandsummary.do?hetId=ACB).  I am using this as a template for D-iso-aspartic acid in my model because I can not find a 3 letter code for the exact D-iso-aspartic acid (I know for L-iso-aspartic acid the code is IAS but no code for D-iso-aspartic acid)

I can search in Phenix eLBOW (Mac Phenix Version 1.10pre) with code ACB and I can find the code and right compound, I tried to generate restraints of ACB using eLBOW and I got a cif and pdb output of the compound. However when I import the compound into coot, delete the methyl group to make the compound a D-isoAsp, and click "edit chi angles", I receive an error: This residue does not have assigned torsion/chi angles".  I do not know what I should do to fix the problem. I thought eLBOW would automatically generate Chi angles but actually it did not in my case.  I appreciate if you have any input on this.