Pure Rotational Spectrum of Water Vapor

Abstract

The pure rotational spectrum of water vapor was measured over the frequency range 5-125 cm-I at a resolution of approximately 0.07 em-I. A complete set of energy levels up to J = 7 was derived. The groundstate rotational constants were calculated and agree well with those derived from near-infrared data. The values of the ground-state rotational constants are Ao= 27.8761±0.OO34 em-I, Bo= 14.5074±0.0090 em-I, and C o =9.2877±0.OO21 em-I. The six quartic distortion constants were also determined along with the higher-order distortion constant associated with the a axis of rotation.

Molecular Orientation and Alignment by Intense Single-Cycle THz Pulses

“…3c) from non-interacting water molecules are not contributing significantly to 2Q and 3Q features. 16…”

“…In the gas phase, water is also of utmost importance for atmospheric science, astrophysics, combustion research, and fundamental chemistry and physics 1,14,15 . Although the pure rotational spectrum of water vapor has been well known for decades 16,17 , nonlinear THz spectroscopy of water rotational dynamics has not been previously reported. Nonlinear rotational spectroscopy in the microwave spectral range is well established 18,19 , but because of the small mass and moments of inertia of water, most of its rotational transition frequencies lie in the terahertz frequency range (see Fig.…”

Quantum rotation of ortho and para -water encapsulated in a fullerene cage

“…In the ortho-H 2 O@C 60 ground state the truncated dipolar Hamiltonian is given by the quantum and thermal average of dipolar Hamiltonian (3,4) …”

Homogeneous nucleation: a problem in nonequilibrium quantum statistical mechanics

“…We have chosen water because: The water molecule (monomer) is an asymmetric rotator; i.e., it has three distinct moments of inertia. Hall and Dowling (1967) present eigenenergies suitable for calculating the rotational partition function from Eq. (7-2S).…”

“…4. Hall and Dowling (1967) Helmholt2 tree energy of rotation for the water molecule computed from Hall and Dowling (1967) data. From rotational constants From energy levels o between molecules along the edges of the square is 2.96 A.…”