Abstract: | Ab initio molecular orbital calculations have been carried out for 17 possible isomeric C3H7O]+ structures. Optimized geometries have been obtained with a split-valence basis set and improved relative energies determined with polarization basis sets and with incorporation of electron correlation. The results agree well with available experimental data. In particular, (CH3)2COH+, CH3CH2CHOH+, CH3CHOCH3+, CH3CH2OCH2+, and have been confirmed as low-energy isomers. Six additional structures appear to be energetically accessible and to offer a reasonable prospect for experimental observation. These are CH2CHCH2OH2+, CH2C(CH3)OH2+, CH3CHCHOH2+, CH2CHOHCH3+, and . |