The theoretical research carried out in this NSF funded project was directed towards collaborating with experimentalists to enhance dramatically the information content of the OH, NH and CH stretching region of the infrared spectrum.  By shining laser light on gas phase molecules in just the right experimental setting, one can measure the precise frequencies of the light that is absorbed by the molecule.   When these frequencies are within certain ranges, then this light is known to lead to excitation of the vibrations of O-H, N-H or C-H bonds.  Our research combined quantum mechanical solutions of both the electrons and the nuclei in an effective way that showed that the precise values of this absorbed light can be used to lean about the local environment of these bonds.  For example, when there are multiple low energy structures of a molecule that are possible, our work has shown which structures the molecule prefers based on the frequencies of light that are absorbed. This work required making a series of approximations and then rigorously testing these approximations by comparing our results directly to experimental findings.  The systems that were studied span from small hydrocarbon radicals to large molecules complexed with water that feature multiple hydrogen bonding sites. This research will provide researchers additional molecular structure information for a wide range of biological and chemical processes.  Finally, this project has provided sound training in fundamental research of both the undergraduate and graduate students involved in the project.                                                           

Last Modified: 10/22/2020
Modified by: Edwin L Sibert