Re: calculate charge using MOPAC



 Hi Jianquan
 
1. MOPAC can run just an "SCF" which does not change the geometry. This is the fastest way to get partial charges.
 
2. The new linear-scaling versions of MOPAC can calculate up to 20,000 atoms in just a few hours on a Windows desktop computer. With "MOPAC 2002", an SCF on a 641 atom protein takes about 3 minutes on a 1000 MHz Pentium III. There is more information at http://www.cachesoftware.com/mopac/index.shtml
 David Gallagher, Fujitsu
 At 12:22 PM 6/4/2002 -0400, Jianquan Chen wrote:
 
 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
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