#!/bin/bash
awk 'BEGIN {srand();} {
if ($4=="" || $6!="") {
  print $0;
}
else {
  atom=$4;
  gsub("[+-].*$","",atom);
  spin=$4;
  gsub("^[A-Za-z]*","",spin);
  if (rand()>0.5) {gsub("+","-",spin);} else {gsub("-","+",spin);};
  print $1,$2,$3,atom spin}
}'
