Rigorous vibrational Fermi resonance criterion revealed: two different approaches yield the same result

Krasnoshchekov, S. V.; Dobrolyubov, Egor O; Syzgantseva, Maria A.; Palvelev, Roman Vital'evich

doi:10.1080/00268976.2020.1743887

Cited by 18 publications

(15 citation statements)

References 56 publications

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“…The most common procedure involves two steps, first on the energetic proximity of the interacting states-here |2 i 〉 and |1 j 〉 -, that is the magnitude of the denominator, and then on the overall weight of the term. Several strategies have been proposed for the latter (Martin et al, 1995;Barone, 2005;Krasnoshchekov et al, 2020). Here, we will employ the test proposed by Martin and coworkers (Martin et al, 1995), which considers the deviation of the term from the variational energy of a model, ad hoc system.…”

Section: Vibrational Energiesmentioning

confidence: 99%

“…On the other side, VPT2 can suffer from resonances, special conditions which lead to an incorrect account of the anharmonic effects. While several strategies have been proposed in the literature and automated schemes are being devised to overcome this issue (Martin et al, 1995;Kuhler et al, 1996;Barone, 2005;Bloino et al, , 2015Krasnoshchekov et al, 2014Krasnoshchekov et al, , 2020, the effect of these corrections on the final energies and intensities has still been scarcely investigated. With these considerations in mind, the study proposed here is divided in several steps, starting from small systems where VPT2 calculations are straightforward and accurate reference data are available.…”

Section: Introductionmentioning

confidence: 99%

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Accuracy and Reliability in the Simulation of Vibrational Spectra: A Comprehensive Benchmark of Energies and Intensities Issuing From Generalized Vibrational Perturbation Theory to Second Order (GVPT2)

Yang

Mendolicchio

Barone

et al. 2021

Front. Astron. Space Sci.

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Vibrational spectroscopy represents an active frontier for the identification and characterization of molecular species in the context of astrochemistry and astrobiology. As new missions will provide more data over broader ranges and at higher resolution, especially in the infrared region, which could be complemented with new spectrometers in the future, support from laboratory experiments and theory is crucial. In particular, computational spectroscopy is playing an increasing role in deepening our understanding of the origin and nature of the observed bands in extreme conditions characterizing the interstellar medium or some planetary atmospheres, not easily reproducible on Earth. In this connection, the best compromise between reliability, feasibility and ease of interpretation is still a matter of concern due to the interplay of several factors in determining the final spectral outcome, with larger molecular systems and non-covalent complexes further exacerbating the dichotomy between accuracy and computational cost. In this context, second-order vibrational perturbation theory (VPT2) together with density functional theory (DFT) has become particularly appealing. The well-known problem of the reliability of exchange-correlation functionals, coupled with the treatment of resonances in VPT2, represents a challenge for the determination of standardized or “black-box” protocols, despite successful examples in the literature. With the aim of getting a clear picture of the achievable accuracy and reliability of DFT-based VPT2 calculations, a multi-step study will be carried out here. Beyond the definition of the functional, the impact of the basis set and the influence of the resonance treatment in VPT2 will be analyzed. For a better understanding of the computational aspects and the results, a short summary of vibrational perturbation theory and the overall treatment of resonances for both energies and intensities will be given. The first part of the benchmark will focus on small molecules, for which very accurate experimental and theoretical data are available, to investigate electronic structure calculation methods. Beyond the reliability of energies, widely used for such systems, the issue of intensities will also be investigated in detail. The best performing electronic structure methods will then be used to treat larger molecular systems, with more complex topologies and resonance patterns.

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Section: Vibrational Energiesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Accuracy and Reliability in the Simulation of Vibrational Spectra: A Comprehensive Benchmark of Energies and Intensities Issuing From Generalized Vibrational Perturbation Theory to Second Order (GVPT2)

Yang

Mendolicchio

Barone

et al. 2021

Front. Astron. Space Sci.

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“…The applied value of resonance criterion Ξ † ≈ 0.07 was deliberately chosen to be slightly looser than the recommended value. 134 This helped to account for rather weak 1–11 Fermi resonance in HDO and ensure uniqueness of the polyad form for this molecule. The list of identified resonance operators corresponding to the 1–2/1–11 Fermi and 2–2 Darling–Dennison resonances is presented in Table 2.…”

Section: Methods Of Calculationmentioning

confidence: 99%

Fundamental studies of vibrational resonance phenomena by multivalued resummation of the divergent Rayleigh–Schrödinger perturbation theory series: deciphering polyad structures of three H₂¹⁶O isotopologues

Chang

Dobrolyubov

Krasnoshchekov

2022

Phys. Chem. Chem. Phys.

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“…Столь же важным является резонанс Ферми ν 4 /2ν 6 , который имеет наибольшее значение параметра " силы резонанса" = 0.4906 [61,73]. Этот резонанс был подробно изучен в ряде работ [14,26,23,28,24,40].…”

Section: колебательные резонансы и полиадное квантовое числоunclassified

Неэмпирический анализ изотопических сдвигов и резонансных эффектов в инфракрасном спектре высокого разрешения фреона-22 (CHF-=SUB=-2-=/SUB=-Cl), обогащенного -=SUP=-13-=/SUP=-C

Краснощеков¹,

Гайнуллин²,

Лаптев³

et al. 2022

Оптика И Спектроскопия

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The IR transmittance spectrum of an isotopic mixture of chlorodifluoromethane (CHF2Cl, Freon-22) with a 33% fraction of 13C and a natural ratio of chlorine isotopes was measured in the frequency range 1400-740 cm–1 with a resolution of 0.001 cm–1 at a temperature of 20C. An ab initio calculation of the structure and sextic potential energy surface and surfaces of the components of the dipole moment has been carried out by the the electronic quantum-mechanical method of Möller-Plesset, MP2/cc-pVTZ. Then the potential was optimized by replacing the harmonic frequencies with the frequencies calculated by the electronic method of coupled clusters, CCSD(T)/aug-cc-pVQZ. The fundamental and combination frequencies were calculated using the operator perturbation theory of Van Vleck (CVPTn) of the second and fourth order (n=2,4). Resonance effects were modeled using an additional variational calculation in the basis up to fourfold VCI excitation (4). The average prediction error for the fundamental frequencies of the 12C isotopologues was ~1.5 cm–1. The achieved accuracy made it possible to reliably predict the isotopic frequency shifts of the 13C isotopologues. It is shown that the strong Fermi resonance ν4/2ν6 dominates in the 12C isotopologues and is practically absent in 13C. The literature assumption [Spectrochim. Acta A, 44: 553] about the splitting of ν1 (CH) due to the resonance ν1/ν2+ν7+ν9 is confirmed. The coefficients of the polyadic quantum number are determined. The analysis made it possible to carry out a preliminary identification of the centers of the vibrational-rotational bands of isotopologues 13CHF235Cl и 13CHF237Cl in the spectrum of the mixture in preparation for individual analyzes of the vibrational-rotational structures of individual vibrational transitions.

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Rigorous vibrational Fermi resonance criterion revealed: two different approaches yield the same result

Cited by 18 publications

References 56 publications

Accuracy and Reliability in the Simulation of Vibrational Spectra: A Comprehensive Benchmark of Energies and Intensities Issuing From Generalized Vibrational Perturbation Theory to Second Order (GVPT2)

Accuracy and Reliability in the Simulation of Vibrational Spectra: A Comprehensive Benchmark of Energies and Intensities Issuing From Generalized Vibrational Perturbation Theory to Second Order (GVPT2)

Fundamental studies of vibrational resonance phenomena by multivalued resummation of the divergent Rayleigh–Schrödinger perturbation theory series: deciphering polyad structures of three H₂¹⁶O isotopologues

Неэмпирический анализ изотопических сдвигов и резонансных эффектов в инфракрасном спектре высокого разрешения фреона-22 (CHF-=SUB=-2-=/SUB=-Cl), обогащенного -=SUP=-13-=/SUP=-C

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Rigorous vibrational Fermi resonance criterion revealed: two different approaches yield the same result

Cited by 18 publications

References 56 publications

Accuracy and Reliability in the Simulation of Vibrational Spectra: A Comprehensive Benchmark of Energies and Intensities Issuing From Generalized Vibrational Perturbation Theory to Second Order (GVPT2)

Accuracy and Reliability in the Simulation of Vibrational Spectra: A Comprehensive Benchmark of Energies and Intensities Issuing From Generalized Vibrational Perturbation Theory to Second Order (GVPT2)

Fundamental studies of vibrational resonance phenomena by multivalued resummation of the divergent Rayleigh–Schrödinger perturbation theory series: deciphering polyad structures of three H216O isotopologues

Неэмпирический анализ изотопических сдвигов и резонансных эффектов в инфракрасном спектре высокого разрешения фреона-22 (CHF-=SUB=-2-=/SUB=-Cl), обогащенного -=SUP=-13-=/SUP=-C

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Fundamental studies of vibrational resonance phenomena by multivalued resummation of the divergent Rayleigh–Schrödinger perturbation theory series: deciphering polyad structures of three H₂¹⁶O isotopologues