$MOPAC group    (relevant if GBASIS=PM3, AM1, or MNDO)                          
     This group affects only semi-empirical jobs, which are                     
selected in $BASIS by keyword GBASIS.                                           
PEPTID = flag for peptide bond correction.                                      
         By default a molecular mechanics-style torsion                         
         potential term is added for every peptide bond                         
         linkage found.  The intent is to correct these                         
         torsions to be closer to planar than they would                        
         otherwise be in the semi-empirical model.  Here,                       
         the peptide bond means any                                             
                      O       H                                                 
                      \\     /                                                  
                      /      \                                                  
         One such torsion is added for O-C-N-H and one for                      
         O-C-N-X.  This term is parameterized as in MOPAC6.                     

generated on 7/7/2017