In the pdb_writer, changed the way atom numbers

with more than 5 digits are handled.

In 'CHARMM' mode, "*****" are output
whereas in pdb mode, an exception is thrown.

modules/io/src/mol/pdb_writer.cc

@@ -80,7 +80,12 @@ void write_atom(std::ostream& ostr, FormattedLine& line,
   line( 0, 6)=record_name;
   // Avoid writing out atomnumbers larger than 5 digits
   if (atomnum > 99999) {
-    line( 6, 5)=fmt::LPaddedInt(atomnum - 100000 * (atomnum / 100000));
+    if (charmm_style) {
+      line( 6, 5)=fmt::LPadded("*****");
+    } else {
+      throw IOException("Atom number is too long for PDB output." 
+                        " At most 5 digits are allowed");
+    }
   } else {
     line( 6, 5)=fmt::LPaddedInt(atomnum);
   }