Final Report Summary of LDRD 02-LW-022 'Quantum Vibrations in Molecules: A New Frontier in Computational Chemistry'.

[摘要] With the trend towards needing information about chemistry at conditions significantly different from 298K and 1 atm., methods need to be developed to generate and interpret this data. This demand for information about chemistry at extreme conditions comes from many fields. The study of atmospheric chemistry requires knowledge of unusual species that are formed when molecules are exposed to ultraviolet radiation. Studying of energetic materials requires knowledge of the thermochemical and structural properties of a myriad of chemical species under a wide range of temperatures. Basic scientific understanding of the very nature of a chemical bond requires detailed information. Studying these problems computationally requires multiple capabilities. The methodology used must provide both high accuracy and computational efficiency. Studying extreme chemistry also suffers from all the challenges of studying chemistry under non-extreme conditions. Therefore, either a new method must be developed or an old method must be applied in an innovative way. The method we have chosen to use is path integral Monte Carlo (PIMC) for the nuclear degrees of freedom and ab initio electronic structure methods for the electronic degrees of freedom. PIMC and ab initio electronic structure are methods of treating the quantum nature of particles. These methods have been chosen, because an accurate treatment requires treating both the electrons and the nuclei as quantum particles.

[发布机构] Technical Information Center Oak Ridge Tennessee

[学科分类] 工程和技术（综合）

[关键词] Chemical physics;Degrees of freedom;Nuclei;Atmospheric chemistry;Accuracy