Rotation--vibration interactions in formaldehyde: Results for low vibrational excitations

Journal Article · Tue Jan 01 04:00:00 EST 1991 · Journal of Chemical Physics; (USA)

DOI:https://doi.org/10.1063/1.460698· OSTI ID:6398703

Aoyagi, M; Gray, S K ^[1]

---

1. Theoretical Chemistry Group, Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439 (US)

We have carried out large-scale variational calculations on formaldehyde including all six vibrational modes and the rotational mode associated with {ital K} (the projection of total angular momentum on a body-fixed axis). A complete form of the Watson Hamiltonian and a realistic potential function based on {ital ab} {ital initio} data are used. Emphasis in this paper is placed on the low vibrational energy regime and the effect of Coriolis interaction. Comparison is made with other theoretical calculations and experiment, where available. Analysis of some of our full mode rovibrational states shows instances of simultaneous vibration and rotation mixing due to a strong {ital a}-axis Coriolis interaction. We show that such mixing can be understood from the perspective of a classical nonlinear resonance between the rotational frequency and the difference in two bending mode (out-of-plane and in-plane) frequencies. This confirms previous full dimension classical and reduced dimension quantum studies and represents an alternative way of understanding Coriolis interaction in the low vibrational energy regime.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 6398703
• Journal Information: Journal of Chemical Physics; (USA), Journal Name: Journal of Chemical Physics; (USA) Vol. 94:1; ISSN JCPSA; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

640302* -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
74 ATOMIC AND MOLECULAR PHYSICS
ALDEHYDES
CORIOLIS FORCE
ENERGY LEVELS
ENERGY TRANSFER
ENERGY-LEVEL TRANSITIONS
EXCITATION
EXCITED STATES
FORMALDEHYDE
ORGANIC COMPOUNDS
ROTATIONAL STATES
VARIATIONAL METHODS
VIBRATIONAL STATES