The J-dependent rotational Hamiltonian method for analyzing rovibrational spectra: Application to HO2, H2O, and O3

Poirier, Bill

doi:10.1016/j.cplett.2019.136700

Cited by 3 publications

(2 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…11 For an accurate ro-vibrational spectrum like that, even after it has already been computed, the process of assigning the vibration mode quantum numbers (v1, v2, v3) and the asymmetric-top rotor quantum numbers (JKaKc) to the individual rotational-vibrational states, is also challenging. 12 For these reasons, a symmetric-top rotor approximation (also known as the K-conserving assumption) remains a popular practical tool for the prediction of ro-vibrational state energies. 13,14,15,16 In this simplified method, the terms in the Hamiltonian operator, responsible for the coupling of rotational and vibrational degrees of freedom, are neglected (assumed to be small), which permits to split the overall Hamiltonian matrix into a number of independent smaller blocks that can be labeled by quantum numbers of the symmetric-top rotor (JK).…”

Section: Introductionmentioning

confidence: 99%

“…In the literature, such nearly exact calculations of the rotational–vibrational spectra have been reported for H 3 + , HeHF, LiNC, HeN 2 + , H 2 O, H 2 S, SO 2 , , HO 2 , Ar 3 , and very recently for O 3 . For an accurate ro-vibrational spectrum like that, even after it has already been computed, the process of assigning the vibration mode quantum numbers ( v 1 , v 2 , v 3 ) and the asymmetric-top rotor quantum numbers ( J KaKc ) to the individual rotational–vibrational states is also challenging …”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Theoretical Treatment of the Coriolis Effect Using Hyperspherical Coordinates, with Application to the Ro-Vibrational Spectrum of Ozone

et al. 2020

View full text Add to dashboard Cite

Several alternative methods for description of interaction between rotation and vibration are compared and contrasted using hyper-spherical coordinates for a triatomic molecule. These methods differ by the choice of z-axis and by the assumption of a prolate or oblate rotor shape of the molecule. For each case, block-structure of the rotational-vibrational Hamiltonian matrix is derived and analyzed, and the advantages and disadvantages of each method are made explicit.This theory is then employed to compute ro-vibrational spectra of singly substituted ozone; roughly, 600 vibrational states of 16 O 18 O 16 O and 16 O 16 O 18 O isomers combined, with rotational excitations up to = 5 and both inversion parities (21600 coupled ro-vibrational states total). Splittings between the states of different parities, so called K-doublings, are calculated and analyzed. The roles of the asymmetric-top rotor term and the Coriolis coupling term are determined individually, and it is found that they both affect these splittings, but in the opposite directions. Thus, the two effects partially cancel out, and the residual splittings are relatively small. Energies of the ro-vibrational states reported in this work for 16 O 18 O 16 O and 16 O 16 O 18 O are in excellent agreement with literature (available for low vibrational excitation). New data obtained here for the highly excited vibrational states enable the first systematic study of the Coriolis effect in symmetric and asymmetric isotopomers of ozone.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Theoretical Treatment of the Coriolis Effect Using Hyperspherical Coordinates, with Application to the Ro-Vibrational Spectrum of Ozone

et al. 2020

View full text Add to dashboard Cite

show abstract

The role of rotation–vibration coupling in symmetric and asymmetric isotopomers of ozone

Gayday

Teplukhin

Kendrick

et al. 2020

The Journal of Chemical Physics

View full text Add to dashboard Cite

A theoretical framework and computer code are developed for accurate calculations of coupled rotational-vibrational states in triatomic molecules using hyper-spherical coordinates and taking into account the Coriolis coupling effect. Concise final formulae are derived for construction of the Hamiltonian matrix using an efficient combination of the FBR and DVR methods with locally optimized basis sets and grids. First, the new code is tested by comparing its results with those of the APH3D program of Kendrick. Then, accurate calculations of the rovibrational spectra are carried out for doubly substituted symmetric ( 18 O 16 O 18 O) and asymmetric ( 18 O 18 O 16 O) ozone isotopomers for total angular momentum up to = 5. Together with similar data recently reported for the singly substituted symmetric ( 16 O 18 O 16 O) and asymmetric ( 16 O 16 O 18 O) ozone isotopomers, these calculations quantify the role of the Coriolis coupling effect in the large mass-independent isotopic enrichment of ozone, observed in both laboratoryexperiments and the atmosphere of Earth. It is found that the Coriolis effect in ozone is relatively small, as evidenced by deviations of its rotational constants from the symmetric-top-rotor behavior, by the magnitudes of parity splittings (Λ-doubling), and by the ratios of ro-vibrational partition functions for asymmetric vs. symmetric ozone molecules. It is concluded that all of these characteristics are influenced by the isotopic masses as much as they are influenced by the overall symmetry of the molecule. It is therefore unlikely that the Coriolis coupling effect could be responsible for symmetry-driven mass-independent fractionation of oxygen isotopes in ozone.

show abstract

Spectroscopy and Scattering Studies Using Interpolated Ab Initio Potentials

Quintas‐Sánchez

Dawes

2021

Annu. Rev. Phys. Chem.

View full text Add to dashboard Cite

The Born–Oppenheimer potential energy surface (PES) has come a long way since its introduction in the 1920s, both conceptually and in predictive power for practical applications. Nevertheless, nearly 100 years later—despite astonishing advances in computational power—the state-of-the-art first-principles prediction of observables related to spectroscopy and scattering dynamics is surprisingly limited. For example, the water dimer, (H2O)2, with only six nuclei and 20 electrons, still presents a formidable challenge for full-dimensional variational calculations of bound states and is considered out of reach for rigorous scattering calculations. The extremely poor scaling of the most rigorous quantum methods is fundamental; however, recent progress in development of approximate methodologies has opened the door to fairly routine high-quality predictions, unthinkable 20 years ago. In this review, in relation to the workflow of spectroscopy and/or scattering studies, we summarize progress and challenges in the component areas of electronic structure calculations, PES fitting, and quantum dynamical calculations. Expected final online publication date for the Annual Review of Physical Chemistry, Volume 72 is April 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

show abstract

The J-dependent rotational Hamiltonian method for analyzing rovibrational spectra: Application to HO2, H2O, and O3

Cited by 3 publications

References 36 publications

Theoretical Treatment of the Coriolis Effect Using Hyperspherical Coordinates, with Application to the Ro-Vibrational Spectrum of Ozone

Theoretical Treatment of the Coriolis Effect Using Hyperspherical Coordinates, with Application to the Ro-Vibrational Spectrum of Ozone

The role of rotation–vibration coupling in symmetric and asymmetric isotopomers of ozone

Spectroscopy and Scattering Studies Using Interpolated Ab Initio Potentials

Contact Info

Product

Resources

About