message: check number of models in original receptor
diff: @@ -24,6 +24,10 @@ rigidname = args.rigid
  flexname = args.flex
  outfile = args.out
  +rigid = prody.parsePDB(rigidname)
  +if rigid.numCoordsets() != 1:
  + raise ValueError(f"More than one model (MODEL/ENDMDL) for {rigidname} is not allowed.")
  +
  out = open(outfile, "w")
  flex = prody.parsePDB(flexname)
  