Install MOPAC2009 on Ubuntu

1. During install, MOPAC gives the message "permission denied"

• Because the directory, subdirectory and file must have read and write permission. Use the "chmod" command to set the permissions, the simplest is "chmod -R 777 /opt/mopac/". Note: don't miss "-R" , it is very important, without it, the directory "mopac" has the read and wirte prermission, but the subdirectory and file don't have read and write permission.