CCSD(T) study of the infrared spectrum of ethyl-methyl-ether isotopic varieties

Band positions for the infrared bands of various ethyl-methyl-ether isotopomers (CH3CH2OCH2D, CH2DCH2OCH3, CH3CH2OCD3, CD3CH2OCH3, CH3CD2OCH3, CH3CH2O13CH3, 13CH3CH2OCH3, and CH313CH2OCH3) are determined using second order perturbation theory. For species showing G18 symmetry, band position are calculated variationally from a CCSD(T)/cc-pVTZ three-dimensional potential energy surface corrected vibrationally. Potential energy barriers, fundamental frequencies, and rotational constants for excited vibrational levels, are also provided. Calculated frequencies for CH3CH2OCD3 confirm experimental assignments and our predictions for the most abundant isotopomer [4].