Vibration-Internal Rotation-Overall Rotation Interactions in CH(2)DOH and CHD(2)OH

Area of Science:

• Molecular Physics
• Quantum Chemistry
• Spectroscopy

Background:

• Accurate molecular modeling requires precise kinetic energy formulations.
• Vibrational, rotational, and internal large-amplitude motions present significant theoretical challenges.
• Isotopologues like CH(2)DOH and CHD(2)OH offer unique insights into molecular dynamics.

Purpose of the Study:

• To develop the zeroth-order kinetic energy for specific methyl alcohol isotopologues.
• To apply the Guan and Quade theory for vibration-rotation-internal motion interactions.
• To lay the groundwork for a full solution to molecular kinetic energy calculations.

Main Methods:

• Utilized the general theory of Guan and Quade.
• Applied two sequential T transformations to the kinetic energy expression.
• Separated internal rotation and overall rotation from other molecular vibrations in zeroth order.
• Calculated zeroth-order kinetic energy coefficients from molecular structure and masses.

Main Results:

• Developed the zeroth-order kinetic energy expression for CH(2)DOH and CHD(2)OH.
• Successfully separated vibrational and rotational motions using T transformations.
• Identified that overall rotation and internal rotation remain coupled in zeroth order.
• Calculated all necessary zeroth-order kinetic energy coefficients.

Conclusions:

• The developed zeroth-order kinetic energy is a crucial first step for a complete molecular dynamics solution.
• The employed transformations effectively simplify the complex kinetic energy formulation.
• This work provides essential coefficients for further analysis of methyl alcohol isotopologue spectra.