Molecular geometries of molecules can be determined using software Gamess, and multiple basis sets were used to determine the best geometry optimization of the molecule Carbon Monosulfide. Ab Initio was the preferred level of theory because it calculated all integrals instead of simple approximations. The basis sets were set up in Ab Initio. The input files for Ab Initio were AM1/PM3 files created in MacMolPlt and the generated files were, in increasing order of size, 6-21G, 6-31G, and DZV basis sets. As the basis set size increased, more options for electrons were available for calculations. Therefore, it is assumed that the best geometry optimization is given by the DZV basis set. All basis sets gave bond lengths of 0.143 nm while the experimental bond length was 0.154 nm. The percent error is 6.84%.

To view the Potential Energy, Molecular Orbital, and Vibrational Frequency of Carbon Monosulfide click the link.

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