Subject: COSMO in MOPAC7

From: [email-masked]
Date: 19 May 2000 17:29:13 -0400

Hi,
     
     I have a difficulty to calculate the heat of formation using the COSMO 
     model in MOPAC7 revision 2 (QCPE). Some modification was necessary in 
     some subroutines in order to avoid incompatible common blocks. I use 
     MOPAC on SGI Indigo 2 and could reproduce HOF without COSMO.
     
     There is no problem for small molecules, though test_cosmo yielded a 
     slightly different result than that given in the test_cosmo.dat 
     (60.059 vs 59.766 kcal/mol). 
     
     ESP (= 78.4) alone could not complete the MOPAC job for some 
     molecules. I had to assign smaller NSPA than the default 42. For one 
     molecule for a single point energy calculation (max # of segments = 
     384), it took only 10 sec. for NSPA = 31, while MOPAC runs hours 
     without results for NSPA=32. I couldn't get any for another one (max # 
     of segments = 400) even for NSPA = 4. There was no error message or 
     warning. When I killed the job, the last line of the output file was 
     "RHF CALCULATION,....".
     
     What am I missing? I appreciate your help.
     
     Currently I am not a CCL subscriber, I appreciate if you could reply 
     this e-mail address.

     Thanks in advance.

     Genzo