Why I do not see the GAMESS calculations listed in the calculations menu as an option? I see the instructions described in the Chem3D manual for calculating IR spectra using GAMESS in Chem3D 20.

Why I do not see the GAMESS calculations listed in the calculations menu as an option? I see the instructions described in the Chem3D manual for calculating IR spectra using GAMESS in Chem3D 20.

Please check the features available for each suite in the Software Requirements guide.  The GAMESS 18 Interface in Chem3D is available only in ChemOffice+ Cloud 20 / ChemOffice Professional (versions 17-19), unfortunately the feature is not available in ChemDraw Prime and Professional suites.