Rotational analysis of the 2ν<sub>5</sub> band of formaldehyde

Saha, S. K.; Barry, Hugh R.; Hancock, Gus; Ritchie, Gad; Western, Colin M.

doi:10.1080/00268970601126767

Cited by 6 publications

(4 citation statements)

References 34 publications

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“…24 corresponding to the states (ν 1 , ν 2 + ν 3 , ν 2 + ν 4 , ν 2 + ν 6 , 2ν 3 , ν 3 + ν 4 , ν 3 + ν 6 , 2ν 4 , ν 4 + ν 6 , ν 5 , and 2ν 6 ) were recently re-determined at a higher accuracy by Perrin et al 31 Similar improvements were made by Flaud et al 33 for the (ν 1 + ν 2 , ν 1 + ν 6 , 3ν 2 , ν 2 + ν 5 , 2ν 2 + ν 6 , ν 2 + ν 4 + ν 6 , ν 3 + ν 5 , and 2ν 3 + ν 6 ) states in the 1.9-2.56 μm region. In addition, the 2ν 5 band was reinvestigated by Saha et al 34 These recent band center values 31,33,34 were used in place of the corresponding J = 0 energies from Ref. 24.…”

Section: The Refined Potential Energy Surfacementioning

confidence: 99%

A new “spectroscopic” potential energy surface for formaldehyde in its ground electronic state

Yachmenev

Yurchenko

Jensen

et al. 2011

The Journal of Chemical Physics

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We report a new "spectroscopic" potential energy surface (PES) of formaldehyde (H(2)(12)C(16)O) in its ground electronic state, obtained by refining an ab initio PES in a least-squares fitting to the experimental spectroscopic data for formaldehyde currently available in the literature. The ab initio PES was computed using the CCSD(T)/aug-cc-pVQZ method at 30 840 geometries that cover the energy range up to 44 000 cm(-1) above equilibrium. Ro-vibrational energies of formaldehyde were determined variationally for this ab initio PES by means of the program TROVE [Theoretical ROtation-Vibration Energies; S. N. Yurchenko, W. Thiel, and P. Jensen, J. Mol. Spectrosc. 245, 126 (2007)]. The parameter values in the analytical representation of the PES were optimized in fittings to 319 ro-vibrational energies with J = 0, 1, 2, and 5. The initial parameter values in the fittings were those of the ab initio PES, the ro-vibrational eigenfunctions obtained from this PES served as a basis set during the fitting process, and constraints were imposed to ensure that the refined PES does not deviate unphysically from the ab initio one in regions of configuration space not sampled by the experimental data. The resulting refined PES, referred to as H(2)CO-2011, reproduces the available experimental J ≤ 5 data with a root-mean-square error of 0.04 cm(-1).

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Section: The Refined Potential Energy Surfacementioning

confidence: 99%

A new “spectroscopic” potential energy surface for formaldehyde in its ground electronic state

Yachmenev

Yurchenko

Jensen

et al. 2011

The Journal of Chemical Physics

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“…For example interactions between vibrational states within the ground electronic state of HCHO have been modelled [19] The same approach can also be used to add terms beyond the standard ones considered above. For example, the standard symmetric top Hamiltonian, equation (62) above, implements centrifugal distortion terms with powers of N up to 8.…”

Section: Matrix Elements and Adding Additional Terms To The Hamiltonianmentioning

confidence: 99%

“…There are no hard limits on the number of any type of object, though the calculation will be slower and take more memory as the number of objects is increased. The limiting step for larger calculations is typically the matrix diagonalization step; to give an indication a model involving ~20 interacting asymmetric top states [19,20] takes a few seconds on a current desktop machine. PGOPHER makes use of parallel processing where possible; many of the calculations split naturally into independent parts, making this reasonably straightforward to implement.…”

Section: Overall Operationmentioning

confidence: 99%

PGOPHER: A program for simulating rotational, vibrational and electronic spectra

Western

2017

Journal of Quantitative Spectroscopy and Radiative Transfer

941

590

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General rightsThis document is made available in accordance with publisher policies. Please cite only the published version using the reference above. AbstractThe PGOPHER program is a general purpose program for simulating and fitting molecular spectra, particularly the rotational structure. The current version can handle linear molecules, symmetric tops and asymmetric tops and many possible transitions, both allowed and forbidden, including multiphoton and Raman spectra in addition to the common electric dipole absorptions. Many different interactions can be included in the calculation, including those arising from electron and nuclear spin, and external electric and magnetic fields. Multiple states and interactions between them can also be accounted for, limited only by available memory. Fitting of experimental data can be to line positions (in many common formats), intensities or band contours and the parameters determined can be level populations as well as rotational constants. PGOPHER is provided with a powerful and flexible graphical user interface to simplify many of the tasks required in simulating, understanding and fitting molecular spectra, including Fortrat diagrams and energy level plots in addition to overlaying experimental and simulated spectra. The program is open source, and can be compiled with open source tools. This paper provides a formal description of the operation of version 9.1.

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“…Similarly, the tables in 79BrHuPi [74] are of very poor quality and their line frequency data could only be accurately reconstructed by extensive comparison with HITRAN [151]; 88ClVa [82] also provides a small portion of 79BrHuPi's spectrum in readable form. 02BaCoHaPe [90] recorded a spectrum of the 5ν 2 overtone; this spectrum was analyzed by 07SaBaHaRi [99], who also provided the data (C.M. Western, private communication, 2020).…”

Section: Source-specific Commentsmentioning

confidence: 99%

An improved rovibrational linelist of formaldehyde, \spec{h212c16o}

Al-Derzi,

Tennyson,

Yurchenko

et al. 2021

Preprint

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Published high-resolution rotation-vibration transitions of H 12 2 C 16 O, the principal isotopologue of methanal, are analyzed using the MARVEL (Measured Active Rotation-Vibration Energy Levels) procedure. The literature results are augmented by new, high-accuracy measurements of pure rotational transitions within the ground, ν 3 , ν 4 , and ν 6 vibrational states. Of the 16 596 non-redundant transitions processed, which come from 43 sources including the present work, 16 403 could be validated, providing 5029 empirical energy levels of H 12 2 C 16 O with statistically well-defined uncertainties. All the empirical rotational-vibrational energy levels determined are used to improve the accuracy of ExoMol's AYTY line list for hot formaldehyde. The complete list of collated experimental transitions, the empirical energy levels determined, as well as the extended and improved line list are provided as Supplementary Material.

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Rotational analysis of the 2ν₅ band of formaldehyde

Cited by 6 publications

References 34 publications

A new “spectroscopic” potential energy surface for formaldehyde in its ground electronic state

A new “spectroscopic” potential energy surface for formaldehyde in its ground electronic state

PGOPHER: A program for simulating rotational, vibrational and electronic spectra

An improved rovibrational linelist of formaldehyde, \spec{h212c16o}

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Rotational analysis of the 2ν5 band of formaldehyde

Cited by 6 publications

References 34 publications

A new “spectroscopic” potential energy surface for formaldehyde in its ground electronic state

A new “spectroscopic” potential energy surface for formaldehyde in its ground electronic state

PGOPHER: A program for simulating rotational, vibrational and electronic spectra

An improved rovibrational linelist of formaldehyde, \spec{h212c16o}

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Product

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Rotational analysis of the 2ν₅ band of formaldehyde