code: public static Atom[] getRepresentativeAtoms(Structure structure) {
  
  		if (structure.isNmr())
  			return StructureTools.getRepresentativeAtomArray(structure);
  
  		else {
  
  			// Get Atoms of all models
  			List<Atom> atomList = new ArrayList<Atom>();
  			for (int m = 0; m < structure.nrModels(); m++) {
  				for (Chain c : structure.getModel(m))
  					atomList.addAll(Arrays.asList(StructureTools
  							.getRepresentativeAtomArray(c)));
  			}
  			return atomList.toArray(new Atom[0]);
  		}
  
  	}
docs: Returns the representative Atom Array of the first model, if the
  structure is NMR, or the Array for each model, if it is a biological
  assembly with multiple models.
  
  @param structure
  @return representative Atom[]