Chem3D 8.0 Manual - CambridgeSoft

AdministratorDescriptionVibrational Analysis *KeywordFORCENOTE: Useful fordetermining zeropoint energies andnormal vibrationalmodes. Use DFORCEto print out vibrationinformation in *.outfile.Creating an Input FileA MOPAC (.MOP) input file is associated with amodel and its dialog box settings.To create a MOPAC input file:1. From the MOPAC menu, choose Create InputFile.No MM correctionNOMMNOTE: By default,MOPAC performs amolecular mechanics(MM) correction forCONH bonds.Resolve density matrix *PI2. Select the appropriate settings and click Create.Increase SCF criteriaIncrease the total CPU timeallowed for the job.NOTE: Resolvedensity matrix intosigma and pi bonds.PRECISENOTE: Increasescriteria by 100 times.This is useful forincreasing theprecision of energiesreported.T = n [M,H,D]NOTE: The defaultis 1h (1 hour) or 3600seconds.Running Input FilesChem3D allows you to run previously createdMOPAC input files. For more information about theMOPAC file format see “Chapter 8: Printing andExporting Models.”To run an input file:1. From the MOPAC menu, choose Run InputFile.The Run MOPAC Input File dialog boxappears.176 • Chapter 11: MOPAC Computations CambridgeSoftCreating an Input File