Title

Vibrational Energy Levels of the Simplest Criegee Intermediate (CH2OO) From Full-dimensional Lanczos, MCTDH, and MULTIMODE Calculations

Abstract

Accurate vibrational energy levels of the simplest Criegee intermediate (CH2OO) were determined on a recently developed ab initio based nine-dimensional potential energy surface using three quantum mechanical methods. the first is the iterative Lanczos method using a conventional basis expansion with an exact Hamiltonian. the second and more efficient method is the multi-configurational time-dependent Hartree (MCTDH) method in which the potential energy surface is refit to conform to the sums-of-products requirement of MCTDH. Finally, the energy levels were computed with a vibrational self-consistent field/virtual configuration interaction method in MULTIMODE. the low-lying levels obtained from the three methods are found to be within a few wave numbers of each other, although some larger discrepancies exist at higher levels. the calculated vibrational levels are very well represented by an anharmonic effective Hamiltonian. © 2015 AIP Publishing LLC.

Department(s)

Chemistry

International Standard Serial Number (ISSN)

219606

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2015, American Institute of Physics (AIP), All rights reserved.


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