calculate charge using MOPAC



Hi,
 I need to add charge to thousands of molecules. MOPAC is free but slow and
 sometimes  changes the moleucular structure. I don't know how MOPAC
 works. I have 2 questions.
 Can I run MOPAC without optimizing the molecular
 structure?
 Is there any way to accelate MOPAC? I don't need very accurate charges.
 Thanks a lot for any response.
 Jianquan Chen