# collective variables config file: one distance
    
colvar {
  name ncdist # needed to identify the variable
    
  distance {
    group1 {
      atomNumbers 1 
    }
    group2 {
      atomNumbers 1231
    }
  } 
}    
    
colvar {
  name ncdist2 # needed to identify the variable
    
  distance {
    group1 {
      atomNumbers 2 
    }
    group2 {
      atomNumbers 1230
    }
  } 
}    
    
myatoms {
  # add all the C-alphas within residues 1 to 76 of segment "U"
  psfSegID              U
  atomNameResidueRange  CA 1-76
}