Related Experiment Video
Updated: Aug 24, 2026

Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry
Published on: April 8, 2020
Calculation of rovibrational energy states for water vapor using the symmetric top approximation in the Pade form
O K Voitsekhovskaya1, V N Cherepanov, A A Kotov
1The Tomsk State University, Tomsk 634050, Russia. vok@elefot.tsu.ru
Abstract:
Considering the water vapor molecule for ka > or = J/2 >> 1 as a symmetric top, the simple analytical Pade form for vibrational rotational energy levels was proposed. The rotational spectroscopic parameters for ground and 010 vibrational states of H2O molecule in the framework of this model have been obtained with good prediction. The absorption coefficient of water vapor in the spectral range 725-925 cm(-1) has been calculated for 1000-6000 K temperatures taking into account the transitions to high-excited states up to J < or = 35 and J < or = 30 for the 000 and 010 vibrational states, respectively. It is shown that the prominent role of transitions to high-excited states is in 8-12 microm atmospheric transparency window.
More Related Videos
06:37Analyzing Melts and Fluids from Ab Initio Molecular Dynamics Simulations with the UMD Package
Published on: September 17, 2021
08:54Vibrational Spectra of a N719-Chromophore/Titania Interface from Empirical-Potential Molecular-Dynamics Simulation, Solvated by a Room Temperature Ionic Liquid
Published on: January 25, 2020
Related Concept Videos
IR Spectroscopy: Hooke's Law Approximation of Molecular Vibration
According to Hooke's law, the vibrational frequency is directly proportional to the...
Van der Waals Equation
First, the attractive forces between molecules, which are stronger at higher densities and reduce the pressure, are considered by adding to the pressure a term equal to the square of the molar density multiplied by a positive coefficient a. Second, the volume...
The Van der Waals Equation
IR Spectroscopy: Molecular Vibration Overview
Stretching vibrations are vibrational motions that occur along the bond line, changing the bond length or distance between two bonded atoms. They are further distinguished as symmetric or asymmetric. In symmetric stretching, the...
Real Gases: Effects of Intermolecular Forces and Molecular Volume Deriving Van der Waals Equation
Reaction Mechanisms: The Steady-State Approximation