Pub Date : 2026-03-01Epub Date: 2025-12-22DOI: 10.1016/j.jqsrt.2025.109796
Vladimir Sautenkov , Sergey Saakyan , Andrei Bobrov , Boris B. Zelener
We discuss nonlinear spectra of selective reflection from high-density rubidium atomic vapor, where the self-broadening of the resonant transition dominates over the Doppler width. In the experiments, the hole-burning technique with probe and pump lasers is used. The reflection of weak probe beam is investigated at four atomic densities in the range cm−3 and various pump beam intensities. To enhance the spectral resolution, the frequency derivative of the reflection coefficient is analyzed. Increasing the atomic number density changes the character of self-broadening from inhomogeneous to homogeneous. At the highest density, the strong pump field splits the observed spectra into two homogeneously broadened symmetric resonances. The appearance of the optical-field-induced resonances can be explained within the framework of “dressed atomic states” approach. At lower densities the spectral profiles are inhomogeneously broadened. Spectral profiles of the frequency derivative are separated by optically saturated dips. The width of such dips is a combination of the homogeneous component of self-broadening and intensity-dependent field broadening. Careful study of the transition from inhomogeneous to homogeneous broadening may initiate further development of the theory of interatomic interactions in high density atomic gas media.
{"title":"Optical-field-induced dips and splits in nonlinear spectra of selective reflection from high-density atomic vapor","authors":"Vladimir Sautenkov , Sergey Saakyan , Andrei Bobrov , Boris B. Zelener","doi":"10.1016/j.jqsrt.2025.109796","DOIUrl":"10.1016/j.jqsrt.2025.109796","url":null,"abstract":"<div><div>We discuss nonlinear spectra of selective reflection from high-density rubidium atomic vapor, where the self-broadening of the resonant transition <span><math><mrow><mn>5</mn><msub><mrow><mi>S</mi></mrow><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow></msub><mo>−</mo><mn>5</mn><msub><mrow><mi>P</mi></mrow><mrow><mn>3</mn><mo>/</mo><mn>2</mn></mrow></msub></mrow></math></span> dominates over the Doppler width. In the experiments, the hole-burning technique with probe and pump lasers is used. The reflection of weak probe beam is investigated at four atomic densities in the range <span><math><mrow><mrow><mo>(</mo><mn>1</mn><mo>.</mo><mn>2</mn><mtext>–</mtext><mn>3</mn><mo>.</mo><mn>6</mn><mo>)</mo></mrow><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>17</mn></mrow></msup></mrow></math></span> cm<sup>−3</sup> and various pump beam intensities. To enhance the spectral resolution, the frequency derivative <span><math><mrow><mtext>d</mtext><mi>R</mi><mo>/</mo><mtext>d</mtext><mi>ν</mi></mrow></math></span> of the reflection coefficient <span><math><mi>R</mi></math></span> is analyzed. Increasing the atomic number density changes the character of self-broadening from inhomogeneous to homogeneous. At the highest density, the strong pump field splits the observed spectra into two homogeneously broadened symmetric resonances. The appearance of the optical-field-induced resonances can be explained within the framework of “dressed atomic states” approach. At lower densities the spectral profiles are inhomogeneously broadened. Spectral profiles of the frequency derivative are separated by optically saturated dips. The width of such dips is a combination of the homogeneous component of self-broadening and intensity-dependent field broadening. Careful study of the transition from inhomogeneous to homogeneous broadening may initiate further development of the theory of interatomic interactions in high density atomic gas media.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"351 ","pages":"Article 109796"},"PeriodicalIF":1.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145813781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2026-01-06DOI: 10.1016/j.jqsrt.2025.109806
Zbigniew Kisiel , Brian J. Esselman , Maria A. Zdanovskaia , R. Claude Woods , Robert J. McMahon , Manamu Kobayashi , Kaori Kobayashi
The present work expands the experimental coverage and analysis of the rotational spectrum for many spectroscopic species of the methylene chloride molecule based on new measurements at 8–750 GHz. Global analyses of measured chlorine nuclear quadrupole hyperfine resolved and hyperfine unresolved transitions are reported for , , , excited vibrational states in CH Cl, g.s., , , , , and in CH Cl37Cl, g.s. and in CH Cl, and g.s. in 13CH Cl. Coriolis coupling between the and fundamentals at 713 and 760 cm−1 has been explicitly treated for the two most abundant isotopic species.
{"title":"Global analyses of rotational transitions of CH2Cl2 up into the THz frequency region","authors":"Zbigniew Kisiel , Brian J. Esselman , Maria A. Zdanovskaia , R. Claude Woods , Robert J. McMahon , Manamu Kobayashi , Kaori Kobayashi","doi":"10.1016/j.jqsrt.2025.109806","DOIUrl":"10.1016/j.jqsrt.2025.109806","url":null,"abstract":"<div><div>The present work expands the experimental coverage and analysis of the rotational spectrum for many spectroscopic species of the methylene chloride molecule based on new measurements at 8–750 GHz. Global analyses of measured chlorine nuclear quadrupole hyperfine resolved and hyperfine unresolved transitions are reported for <span><math><mrow><msub><mrow><mi>v</mi></mrow><mrow><mn>4</mn></mrow></msub><mo>=</mo><mn>3</mn></mrow></math></span>, <span><math><mrow><msub><mrow><mi>v</mi></mrow><mrow><mn>3</mn></mrow></msub><mo>=</mo><mn>1</mn></mrow></math></span>, <span><math><mrow><msub><mrow><mi>v</mi></mrow><mrow><mn>9</mn></mrow></msub><mo>=</mo><mn>1</mn></mrow></math></span>, <span><math><mrow><msub><mrow><mi>v</mi></mrow><mrow><mn>7</mn></mrow></msub><mo>=</mo><mn>1</mn></mrow></math></span> excited vibrational states in CH<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> <span><math><msup><mrow></mrow><mrow><mn>35</mn></mrow></msup></math></span>Cl<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>, g.s., <span><math><mrow><msub><mrow><mi>v</mi></mrow><mrow><mn>4</mn></mrow></msub><mo>=</mo><mn>1</mn></mrow></math></span>, <span><math><mrow><msub><mrow><mi>v</mi></mrow><mrow><mn>4</mn></mrow></msub><mo>=</mo><mn>2</mn></mrow></math></span>, <span><math><mrow><msub><mrow><mi>v</mi></mrow><mrow><mn>4</mn></mrow></msub><mo>=</mo><mn>3</mn></mrow></math></span>, <span><math><mrow><msub><mrow><mi>v</mi></mrow><mrow><mn>3</mn></mrow></msub><mo>=</mo><mn>1</mn></mrow></math></span>, and <span><math><mrow><msub><mrow><mi>v</mi></mrow><mrow><mn>9</mn></mrow></msub><mo>=</mo><mn>1</mn></mrow></math></span> in CH<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> <span><math><msup><mrow></mrow><mrow><mn>35</mn></mrow></msup></math></span>Cl<sup>37</sup>Cl, g.s. and <span><math><mrow><msub><mrow><mi>v</mi></mrow><mrow><mn>4</mn></mrow></msub><mo>=</mo><mn>1</mn></mrow></math></span> in CH<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> <span><math><msup><mrow></mrow><mrow><mn>37</mn></mrow></msup></math></span>Cl<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>, and g.s. in <sup>13</sup>CH<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> <span><math><msup><mrow></mrow><mrow><mn>35</mn></mrow></msup></math></span>Cl<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>. Coriolis coupling between the <span><math><msub><mrow><mi>ν</mi></mrow><mrow><mn>3</mn></mrow></msub></math></span> and <span><math><msub><mrow><mi>ν</mi></mrow><mrow><mn>9</mn></mrow></msub></math></span> fundamentals at 713 and 760 cm<sup>−1</sup> has been explicitly treated for the two most abundant isotopic species.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"352 ","pages":"Article 109806"},"PeriodicalIF":1.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145928116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2025-11-12DOI: 10.1016/j.jqsrt.2025.109738
Zhiguo Xu, Fuquan Zhang
Inspired by the spiny structure in the nature, this study applies the anti-reflection properties of cicada wing structures to near-field radiative heat transfer. The surface microstructure of different cicada wings is observed by SEM, their reflectivity is measured and a model for spiny particles is simplified and established. Thermal discrete dipole approximations method and magneto-optical materials InSb under a magnetic field is used to investigate spiny particles. The nonreciprocal near-field radiative heat transfer between four spiny particles is considered. Effects of spine radius, magnetic field and spine gap are studied. The interaction between scattering of different peaks in spiny particles leads to the valleys and peaks in relative conductance. As the magnetic field increases, the redshift and blueshift of the split peaks reduce the surface polaritons scattering interaction between the resonance main peak and the split peaks. The net clockwise conductance and overall persistent heat transfer ratio increases when the spine radius increases. The overall persistent heat transfer ratio of particles decreases when the gap increases.
{"title":"Reciprocal and nonreciprocal near-field radiative heat transfer between bio-inspired spiny particles under a magnetic field","authors":"Zhiguo Xu, Fuquan Zhang","doi":"10.1016/j.jqsrt.2025.109738","DOIUrl":"10.1016/j.jqsrt.2025.109738","url":null,"abstract":"<div><div>Inspired by the spiny structure in the nature, this study applies the anti-reflection properties of cicada wing structures to near-field radiative heat transfer. The surface microstructure of different cicada wings is observed by SEM, their reflectivity is measured and a model for spiny particles is simplified and established. Thermal discrete dipole approximations method and magneto-optical materials InSb under a magnetic field is used to investigate spiny particles. The nonreciprocal near-field radiative heat transfer between four spiny particles is considered. Effects of spine radius, magnetic field and spine gap are studied. The interaction between scattering of different peaks in spiny particles leads to the valleys and peaks in relative conductance. As the magnetic field increases, the redshift and blueshift of the split peaks reduce the surface polaritons scattering interaction between the resonance main peak and the split peaks. The net clockwise conductance and overall persistent heat transfer ratio increases when the spine radius increases. The overall persistent heat transfer ratio of particles decreases when the gap increases.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"350 ","pages":"Article 109738"},"PeriodicalIF":1.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145515783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2025-12-08DOI: 10.1016/j.jqsrt.2025.109785
Héctor Antonio Solano Lamphar
Artificial Light at Night (ALAN) poses significant public health challenges by disrupting circadian rhythms and increasing melatonin suppression. This study introduces a dynamic modeling framework employing synthetic population simulations to quantify the health impacts of ALAN under varying exposure scenarios. The model integrates spatial, temporal, behavioral, and policy dimensions, enabling the evaluation of interventions such as warm LED lighting (, ), lighting ordinances, and community-wide curfews. Simulations demonstrate that these interventions can reduce melatonin suppression by up to 25% in high-risk zones. Clustering analysis identifies high-suppression areas, providing critical insights for urban planning and policymaking. Sensitivity analyses highlight the pivotal role of policy compliance and behavioral adaptations in mitigating ALAN’s health impacts. Using synthetic populations ensures ethical compliance by avoiding real human data, while the model’s scalability supports application across diverse urban contexts. Future work will integrate ground based illuminance measurements to enhance predictive accuracy and support equitable strategies for mitigating ALAN’s health impacts.
{"title":"Modeling the health impacts of urban light pollution: Synthetic populations and behavioral interventions","authors":"Héctor Antonio Solano Lamphar","doi":"10.1016/j.jqsrt.2025.109785","DOIUrl":"10.1016/j.jqsrt.2025.109785","url":null,"abstract":"<div><div>Artificial Light at Night (ALAN) poses significant public health challenges by disrupting circadian rhythms and increasing melatonin suppression. This study introduces a dynamic modeling framework employing synthetic population simulations to quantify the health impacts of ALAN under varying exposure scenarios. The model integrates spatial, temporal, behavioral, and policy dimensions, enabling the evaluation of interventions such as warm LED lighting (<span><math><mrow><mo>≤</mo><mn>3000</mn><mspace></mspace><mtext>K</mtext></mrow></math></span>, <span><math><mrow><mo>≤</mo><mn>10</mn><mtext>%</mtext><mo>,</mo><mtext>emission at 450–490 nm</mtext></mrow></math></span>), lighting ordinances, and community-wide curfews. Simulations demonstrate that these interventions can reduce melatonin suppression by up to 25% in high-risk zones. Clustering analysis identifies high-suppression areas, providing critical insights for urban planning and policymaking. Sensitivity analyses highlight the pivotal role of policy compliance and behavioral adaptations in mitigating ALAN’s health impacts. Using synthetic populations ensures ethical compliance by avoiding real human data, while the model’s scalability supports application across diverse urban contexts. Future work will integrate ground based illuminance measurements to enhance predictive accuracy and support equitable strategies for mitigating ALAN’s health impacts.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"351 ","pages":"Article 109785"},"PeriodicalIF":1.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145704977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2026-01-17DOI: 10.1016/j.jqsrt.2026.109830
Seda Kın Barka , İpek K. Öztürk , Feyza Güzelçimen , Günay Başar , Sophie Kröger , Gönül Başar
A hollow cathode discharge lamp, a tunable Ti-Sa laser and laser-induced fluorescence spectroscopy were used to examine the hyperfine structure of atomic terbium. A total of 39 spectral lines in the wavelength range between 695 nm and 780 nm were examined. For 11 levels of even parity and 26 levels of odd parity, the magnetic dipole hyperfine structure constants , and the electric quadrupole hyperfine structure constants , were determined. For 13 of these levels, the hyperfine structure constants had not been previously published. Furthermore, for two levels, the hfs constants and from the literature were found to be completely different from our values. Given that our spectra had better resolution and sensitivity compared to the relevant literature source, and that our values were determined using two different lines, we consider our values to be the more reliable ones.
{"title":"New hyperfine structure data of atomic terbium measured by laser spectroscopic methods","authors":"Seda Kın Barka , İpek K. Öztürk , Feyza Güzelçimen , Günay Başar , Sophie Kröger , Gönül Başar","doi":"10.1016/j.jqsrt.2026.109830","DOIUrl":"10.1016/j.jqsrt.2026.109830","url":null,"abstract":"<div><div>A hollow cathode discharge lamp, a tunable Ti-Sa laser and laser-induced fluorescence spectroscopy were used to examine the hyperfine structure of atomic terbium. A total of 39 spectral lines in the wavelength range between 695 nm and 780 nm were examined. For 11 levels of even parity and 26 levels of odd parity, the magnetic dipole hyperfine structure constants <span><math><mi>A</mi></math></span>, and the electric quadrupole hyperfine structure constants <span><math><mi>B</mi></math></span>, were determined. For 13 of these levels, the hyperfine structure constants had not been previously published. Furthermore, for two levels, the hfs constants <span><math><mi>A</mi></math></span> and <span><math><mi>B</mi></math></span> from the literature were found to be completely different from our values. Given that our spectra had better resolution and sensitivity compared to the relevant literature source, and that our values were determined using two different lines, we consider our values to be the more reliable ones.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"352 ","pages":"Article 109830"},"PeriodicalIF":1.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145995418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2025-11-05DOI: 10.1016/j.jqsrt.2025.109722
Zili He , Sandrine Vinatier , Vincent Eymet , Vincent Forest , Bruno Bézard , Pascal Rannou , Sébastien Rodriguez , Emmanuel Marcq , Richard Fournier , Stéphane Blanco , Nada Mourtaday , Yaniss Nyffenegger-Péré , Sébastien Lebonnois , Anni Määttänen
The study of planetary atmospheres and surfaces depends on integrating radiative transfer modelling with inversion techniques. Traditional radiative transfer models, which assume simplified geometries (e.g., parallel-plan approximation), are limited in accurately capturing the heterogeneous and spherical nature of planetary atmospheres and surfaces, especially in spectral ranges where the scattering effects are important. Numerous modelling strategies are available with full accuracy in the representation of 3D features, but coupling such realistic radiative transfer model with inversion techniques raises challenges in calculation time and gradient assessment. Thanks to the recent active research at the interface between statistical physics and computer graphics, we here tackle these challenges based on the propositions of null-collision (Galtier et al., 2013) and spatial partitioning of extinction-coefficients overestimates (Villefranque et al., 2019). Straightforwardly, these propositions are implemented here for planetary atmospheres and we also provide a slightly modified version of the algorithm that simultaneously estimates the radiance and its gradient with respect to the radiative properties (e.g., absorption coefficients, scattering coefficients and surface reflectivities). Gradient estimation preserves the insensitivity of calculation time to the geometric complexity. The method is applied to Titan. Its performance and limitations are discussed together with the perspectives of being integrated into the inversion routine of planetary data.
{"title":"Simultaneous estimation of radiance and its sensitivities to radiative properties in a spherical-heterogeneous atmospheric radiative transfer model by Monte Carlo method: Application to Titan","authors":"Zili He , Sandrine Vinatier , Vincent Eymet , Vincent Forest , Bruno Bézard , Pascal Rannou , Sébastien Rodriguez , Emmanuel Marcq , Richard Fournier , Stéphane Blanco , Nada Mourtaday , Yaniss Nyffenegger-Péré , Sébastien Lebonnois , Anni Määttänen","doi":"10.1016/j.jqsrt.2025.109722","DOIUrl":"10.1016/j.jqsrt.2025.109722","url":null,"abstract":"<div><div>The study of planetary atmospheres and surfaces depends on integrating radiative transfer modelling with inversion techniques. Traditional radiative transfer models, which assume simplified geometries (e.g., parallel-plan approximation), are limited in accurately capturing the heterogeneous and spherical nature of planetary atmospheres and surfaces, especially in spectral ranges where the scattering effects are important. Numerous modelling strategies are available with full accuracy in the representation of 3D features, but coupling such realistic radiative transfer model with inversion techniques raises challenges in calculation time and gradient assessment. Thanks to the recent active research at the interface between statistical physics and computer graphics, we here tackle these challenges based on the propositions of null-collision (Galtier et al., 2013) and spatial partitioning of extinction-coefficients overestimates (Villefranque et al., 2019). Straightforwardly, these propositions are implemented here for planetary atmospheres and we also provide a slightly modified version of the algorithm that simultaneously estimates the radiance and its gradient with respect to the radiative properties (e.g., absorption coefficients, scattering coefficients and surface reflectivities). Gradient estimation preserves the insensitivity of calculation time to the geometric complexity. The method is applied to Titan. Its performance and limitations are discussed together with the perspectives of being integrated into the inversion routine of planetary data.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"350 ","pages":"Article 109722"},"PeriodicalIF":1.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145447993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2025-12-27DOI: 10.1016/j.jqsrt.2025.109800
Alexandros Androutsopoulos , Isuru R. Ariyarathna , Mark C. Zammit , Evangelos Miliordos , Amanda J. Neukirch , Jeffery A. Leiding
<div><div>The electronic structure and spin-orbit states of the CH radical have been systematically investigated using multi-reference configuration interaction (MRCI) and single-reference coupled-cluster (CC) methods. These calculations were performed in conjunction with large correlation-consistent basis sets of quadruple-, quintuple-, and sextuple-ζ quality. To achieve high accuracy, electronic energies for all states were extrapolated to the complete basis set (CBS) limit, enabling the detailed construction of potential energy curves and determination of reliable spectroscopic constants. Spin-orbit coupling effects were explicitly incorporated, and vibrational energy levels were computed via Numerov analysis. The resulting values exhibit good to excellent agreement with available experimental data. Dipole moment and transition dipole moment curves were evaluated to assess the opacity characteristics of CH, revealing that transitions such as <span><math><mrow><mi>X</mi><msup><mrow></mrow><mn>2</mn></msup><mstyle><mi>Π</mi></mstyle><mspace></mspace><mrow><mo>(</mo><mrow><msup><mi>u</mi><mrow><mo>″</mo></mrow></msup><mo>=</mo><mn>0</mn></mrow><mo>)</mo></mrow><mo>→</mo><mspace></mspace><mi>A</mi><msup><mrow></mrow><mn>2</mn></msup><mrow><mstyle><mi>Δ</mi></mstyle><mspace></mspace></mrow><mrow><mo>(</mo><mrow><msup><mi>u</mi><mo>′</mo></msup><mo>=</mo><mn>0</mn></mrow><mo>)</mo></mrow></mrow></math></span>, <span><math><mrow><mi>X</mi><msup><mrow></mrow><mn>2</mn></msup><mstyle><mi>Π</mi></mstyle><mspace></mspace><mrow><mo>(</mo><mrow><msup><mi>u</mi><mrow><mo>″</mo></mrow></msup><mo>=</mo><mn>0</mn></mrow><mo>)</mo></mrow><mspace></mspace><mo>→</mo><mspace></mspace><mi>B</mi><msup><mrow></mrow><mn>2</mn></msup><msup><mrow><mstyle><mi>Σ</mi></mstyle></mrow><mo>−</mo></msup><mspace></mspace><mrow><mo>(</mo><mrow><msup><mi>u</mi><mo>′</mo></msup><mo>=</mo><mn>0</mn></mrow><mo>)</mo></mrow></mrow></math></span>, <span><math><mrow><mi>X</mi><msup><mrow></mrow><mn>2</mn></msup><mstyle><mi>Π</mi></mstyle><mspace></mspace><mrow><mo>(</mo><mrow><msup><mi>u</mi><mrow><mo>″</mo></mrow></msup><mo>=</mo><mn>0</mn></mrow><mo>)</mo></mrow><mspace></mspace><mo>→</mo><mspace></mspace><mi>C</mi><msup><mrow></mrow><mn>2</mn></msup><msup><mrow><mstyle><mi>Σ</mi></mstyle></mrow><mo>+</mo></msup><mspace></mspace><mrow><mo>(</mo><mrow><msup><mi>u</mi><mo>′</mo></msup><mo>=</mo><mn>0</mn></mrow><mo>)</mo></mrow></mrow></math></span>, and <span><math><mrow><mi>X</mi><msup><mrow></mrow><mn>2</mn></msup><mstyle><mi>Π</mi></mstyle><mspace></mspace><mrow><mo>(</mo><mrow><msup><mi>u</mi><mrow><mo>″</mo></mrow></msup><mo>=</mo><mn>0</mn></mrow><mo>)</mo></mrow><mspace></mspace><mo>→</mo><mspace></mspace><mi>D</mi><msup><mrow></mrow><mn>2</mn></msup><msup><mrow><mstyle><mi>Σ</mi></mstyle></mrow><mo>+</mo></msup><mrow><mo>(</mo><mrow><msup><mi>u</mi><mo>′</mo></msup><mo>=</mo><mn>3</mn></mrow><mo>)</mo></mrow></mrow></math></span> are particularly probable. Finally, the total i
采用多参考组态相互作用（MRCI）和单参考耦合簇（CC）方法系统地研究了CH自由基的电子结构和自旋轨道态。这些计算是与四倍，五倍和六倍ζ质量的大型相关一致的基础集一起进行的。为了达到较高的精度，将所有状态的电子能量外推到完全基集（CBS）极限，从而可以详细构建势能曲线并确定可靠的光谱常数。明确地考虑了自旋轨道耦合效应，并通过Numerov分析计算了振动能级。所得值与现有实验数据具有良好的一致性。偶极矩和跃迁偶极矩曲线进行评估评估CH的不透明特性,揭示转换如X2Π(u”= 0)→A2Δ(u = 0), X2Π(u”= 0)→B2Σ−(u = 0), X2Π(u”= 0)→C2Σ+ (u ' = 0),和X2Π(u”= 0)→D2Σ+ (u ' = 3)尤其可能。最后，基于高精度从头算结果，在宽温度范围（10-30,000 K）内计算了CH的总内配分函数和（TIPS）。
{"title":"Low-lying states and total internal partition sums of CH","authors":"Alexandros Androutsopoulos , Isuru R. Ariyarathna , Mark C. Zammit , Evangelos Miliordos , Amanda J. Neukirch , Jeffery A. Leiding","doi":"10.1016/j.jqsrt.2025.109800","DOIUrl":"10.1016/j.jqsrt.2025.109800","url":null,"abstract":"<div><div>The electronic structure and spin-orbit states of the CH radical have been systematically investigated using multi-reference configuration interaction (MRCI) and single-reference coupled-cluster (CC) methods. These calculations were performed in conjunction with large correlation-consistent basis sets of quadruple-, quintuple-, and sextuple-ζ quality. To achieve high accuracy, electronic energies for all states were extrapolated to the complete basis set (CBS) limit, enabling the detailed construction of potential energy curves and determination of reliable spectroscopic constants. Spin-orbit coupling effects were explicitly incorporated, and vibrational energy levels were computed via Numerov analysis. The resulting values exhibit good to excellent agreement with available experimental data. Dipole moment and transition dipole moment curves were evaluated to assess the opacity characteristics of CH, revealing that transitions such as <span><math><mrow><mi>X</mi><msup><mrow></mrow><mn>2</mn></msup><mstyle><mi>Π</mi></mstyle><mspace></mspace><mrow><mo>(</mo><mrow><msup><mi>u</mi><mrow><mo>″</mo></mrow></msup><mo>=</mo><mn>0</mn></mrow><mo>)</mo></mrow><mo>→</mo><mspace></mspace><mi>A</mi><msup><mrow></mrow><mn>2</mn></msup><mrow><mstyle><mi>Δ</mi></mstyle><mspace></mspace></mrow><mrow><mo>(</mo><mrow><msup><mi>u</mi><mo>′</mo></msup><mo>=</mo><mn>0</mn></mrow><mo>)</mo></mrow></mrow></math></span>, <span><math><mrow><mi>X</mi><msup><mrow></mrow><mn>2</mn></msup><mstyle><mi>Π</mi></mstyle><mspace></mspace><mrow><mo>(</mo><mrow><msup><mi>u</mi><mrow><mo>″</mo></mrow></msup><mo>=</mo><mn>0</mn></mrow><mo>)</mo></mrow><mspace></mspace><mo>→</mo><mspace></mspace><mi>B</mi><msup><mrow></mrow><mn>2</mn></msup><msup><mrow><mstyle><mi>Σ</mi></mstyle></mrow><mo>−</mo></msup><mspace></mspace><mrow><mo>(</mo><mrow><msup><mi>u</mi><mo>′</mo></msup><mo>=</mo><mn>0</mn></mrow><mo>)</mo></mrow></mrow></math></span>, <span><math><mrow><mi>X</mi><msup><mrow></mrow><mn>2</mn></msup><mstyle><mi>Π</mi></mstyle><mspace></mspace><mrow><mo>(</mo><mrow><msup><mi>u</mi><mrow><mo>″</mo></mrow></msup><mo>=</mo><mn>0</mn></mrow><mo>)</mo></mrow><mspace></mspace><mo>→</mo><mspace></mspace><mi>C</mi><msup><mrow></mrow><mn>2</mn></msup><msup><mrow><mstyle><mi>Σ</mi></mstyle></mrow><mo>+</mo></msup><mspace></mspace><mrow><mo>(</mo><mrow><msup><mi>u</mi><mo>′</mo></msup><mo>=</mo><mn>0</mn></mrow><mo>)</mo></mrow></mrow></math></span>, and <span><math><mrow><mi>X</mi><msup><mrow></mrow><mn>2</mn></msup><mstyle><mi>Π</mi></mstyle><mspace></mspace><mrow><mo>(</mo><mrow><msup><mi>u</mi><mrow><mo>″</mo></mrow></msup><mo>=</mo><mn>0</mn></mrow><mo>)</mo></mrow><mspace></mspace><mo>→</mo><mspace></mspace><mi>D</mi><msup><mrow></mrow><mn>2</mn></msup><msup><mrow><mstyle><mi>Σ</mi></mstyle></mrow><mo>+</mo></msup><mrow><mo>(</mo><mrow><msup><mi>u</mi><mo>′</mo></msup><mo>=</mo><mn>3</mn></mrow><mo>)</mo></mrow></mrow></math></span> are particularly probable. Finally, the total i","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"352 ","pages":"Article 109800"},"PeriodicalIF":1.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145845039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2026-01-06DOI: 10.1016/j.jqsrt.2026.109811
V.G. Ushakov , A. Yu. Ermilov , E.S. Medvedev
We investigate the LiF spectrum up to 7800 cm−1 above the first dissociation limit. The ab initio calculations of the adiabatic potentials and other molecular functions are performed in a wide range of interatomic separations, -17 bohr. We consider the model of two interacting electronic states including both the bound states and the resonances of two kinds, the tunneling resonances and the predissociative ones. The Born–Oppenheimer potentials are modeled with use of two auxiliary functions containing 15 variable parameters each, whose values are defined by least-squares fitting for the best reproduction of the adiabatic potentials calculated ab initio, as well as the experimental rovibrational transition frequencies. Then we determine the diabatic potentials and the diabatic coupling via the adiabatic potentials and the angle of the adiabatic-to-diabatic basis rotation obtained by integration of the nonadiabatic coupling matrix element. The energies of the bound states, as well as the positions and widths of the resonances are calculated. The observed transition frequencies are reproduced with the standard deviation of 0.0009 cm−1 for LiF, 0.0006 cm−1 for LiF, and within the experimental uncertainties for the most of the lines. The line lists for the bound-bound - rovibrational transitions are calculated for quantum numbers ( for the 0-0 and 1-0 bands).
{"title":"Effect of the avoided crossing on the rovibrational energy levels, resonances, and predissociation lifetimes within the ground and first excited electronic states of lithium fluoride","authors":"V.G. Ushakov , A. Yu. Ermilov , E.S. Medvedev","doi":"10.1016/j.jqsrt.2026.109811","DOIUrl":"10.1016/j.jqsrt.2026.109811","url":null,"abstract":"<div><div>We investigate the LiF spectrum up to 7800 cm<sup>−1</sup> above the first dissociation limit. The <em>ab initio</em> calculations of the adiabatic potentials and other molecular functions are performed in a wide range of interatomic separations, <span><math><mrow><mi>r</mi><mo>=</mo><mn>1</mn></mrow></math></span>-17 bohr. We consider the model of two interacting electronic states including both the bound states and the resonances of two kinds, the tunneling resonances and the predissociative ones. The Born–Oppenheimer potentials are modeled with use of two auxiliary functions containing 15 variable parameters each, whose values are defined by least-squares fitting for the best reproduction of the adiabatic potentials calculated <em>ab initio</em>, as well as the experimental rovibrational transition frequencies. Then we determine the diabatic potentials and the diabatic coupling <em>via</em> the adiabatic potentials and the angle of the adiabatic-to-diabatic basis rotation obtained by integration of the nonadiabatic coupling matrix element. The energies of the bound states, as well as the positions and widths of the resonances are calculated. The observed transition frequencies are reproduced with the standard deviation of 0.0009 cm<sup>−1</sup> for <span><math><msup><mrow></mrow><mrow><mn>7</mn></mrow></msup></math></span>LiF, 0.0006 cm<sup>−1</sup> for <span><math><msup><mrow></mrow><mrow><mn>6</mn></mrow></msup></math></span>LiF, and within the experimental uncertainties for the most of the lines. The line lists for the bound-bound <span><math><mi>X</mi></math></span>-<span><math><mi>X</mi></math></span> rovibrational transitions are calculated for quantum numbers <span><math><mrow><mi>v</mi><mo>≤</mo><mn>50</mn><mo>,</mo><mi>Δ</mi><mi>v</mi><mo>≤</mo><mn>15</mn><mo>,</mo><mi>J</mi><mo>≤</mo><mn>170</mn></mrow></math></span> (<span><math><mrow><mi>J</mi><mo>≤</mo><mn>200</mn></mrow></math></span> for the 0-0 and 1-0 bands).</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"352 ","pages":"Article 109811"},"PeriodicalIF":1.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145928717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2026-01-09DOI: 10.1016/j.jqsrt.2026.109812
B. Atalay
Energies for states of the , odd and the , , and even configurations in neutral indium are obtained using the fully relativistic multiconfiguration Dirac–Hartree–Fock (MCDHF) method. Transition probabilities and oscillator strengths among all these states are given. The magnetic dipole and electric quadrupole hyperfine structure constants are evaluated. To ensure robustness and reliability of the results, different computational strategies and correlation models were used. Employing a natural orbital basis improves the accuracy of computed values significantly and gives better agreement with the experimental values.
{"title":"Relativistic multiconfiguration calculations of energy levels, transition rates and hyperfine constants in neutral indium","authors":"B. Atalay","doi":"10.1016/j.jqsrt.2026.109812","DOIUrl":"10.1016/j.jqsrt.2026.109812","url":null,"abstract":"<div><div>Energies for states of the <span><math><mrow><mn>5</mn><msup><mrow><mi>s</mi></mrow><mrow><mn>2</mn></mrow></msup><mi>n</mi><mi>p</mi></mrow></math></span> <span><math><mrow><mo>(</mo><mi>n</mi><mo>=</mo><mn>5</mn><mo>−</mo><mn>8</mn><mo>)</mo></mrow></math></span>, <span><math><mrow><mn>5</mn><msup><mrow><mi>s</mi></mrow><mrow><mn>2</mn></mrow></msup><mn>4</mn><mi>f</mi></mrow></math></span> odd and the <span><math><mrow><mn>5</mn><msup><mrow><mi>s</mi></mrow><mrow><mn>2</mn></mrow></msup><mi>n</mi><mi>s</mi></mrow></math></span> <span><math><mrow><mo>(</mo><mi>n</mi><mo>=</mo><mn>6</mn><mo>−</mo><mn>8</mn><mo>)</mo></mrow></math></span>, <span><math><mrow><mn>5</mn><msup><mrow><mi>s</mi></mrow><mrow><mn>2</mn></mrow></msup><mi>n</mi><mi>d</mi></mrow></math></span> <span><math><mrow><mo>(</mo><mi>n</mi><mo>=</mo><mn>5</mn><mo>,</mo><mn>6</mn><mo>)</mo></mrow></math></span>, and <span><math><mrow><mn>5</mn><mi>s</mi><mn>5</mn><msup><mrow><mi>p</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></math></span> even configurations in neutral indium are obtained using the fully relativistic multiconfiguration Dirac–Hartree–Fock (MCDHF) method. Transition probabilities and oscillator strengths among all these states are given. The magnetic dipole and electric quadrupole hyperfine structure constants are evaluated. To ensure robustness and reliability of the results, different computational strategies and correlation models were used. Employing a natural orbital basis improves the accuracy of computed values significantly and gives better agreement with the experimental values.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"352 ","pages":"Article 109812"},"PeriodicalIF":1.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2025-12-02DOI: 10.1016/j.jqsrt.2025.109781
Ivan V. Tarabukin , Denis G. Poydashev , Leonid A. Surin
The hyperfine structure of the (para)-NH3–(ortho)-H2 van der Waals molecular complex has been observed and analyzed for the first time. The measurements of the pure rotational transitions were carried out in the frequency range of 75-190 GHz using a newly developed millimeter-wave jet spectrometer with a molecular beam aligned coaxially with the direction of millimeter-waves propagation. 14N nuclear quadrupole coupling constant of NH3, spin-spin and spin-rotation interaction constants of the two protons of the H2 molecule were determined for (para)-NH3–(ortho)-H2 in its ground Π state. The obtained parameters contain useful information about angular orientation of the NH3 and H2 monomers within the van der Waals complex and provide an additional tool for evaluating the quality of the NH3–H2 interaction potential. The latter determines the reliability of the calculated excitation and de-excitation rates of ammonia during collisions with hydrogen in the dense interstellar clouds.
{"title":"Rotational spectrum and hyperfine structure of the (para)-NH3–(ortho)-H2 van der Waals molecular complex","authors":"Ivan V. Tarabukin , Denis G. Poydashev , Leonid A. Surin","doi":"10.1016/j.jqsrt.2025.109781","DOIUrl":"10.1016/j.jqsrt.2025.109781","url":null,"abstract":"<div><div>The hyperfine structure of the (<em>para</em>)-NH<sub>3</sub>–(<em>ortho</em>)-H<sub>2</sub> van der Waals molecular complex has been observed and analyzed for the first time. The measurements of the pure rotational transitions were carried out in the frequency range of 75-190 GHz using a newly developed millimeter-wave jet spectrometer with a molecular beam aligned coaxially with the direction of millimeter-waves propagation. <sup>14</sup>N nuclear quadrupole coupling constant of NH<sub>3</sub>, spin-spin and spin-rotation interaction constants of the two protons of the H<sub>2</sub> molecule were determined for (<em>para</em>)-NH<sub>3</sub>–(<em>ortho</em>)-H<sub>2</sub> in its ground Π state. The obtained parameters contain useful information about angular orientation of the NH<sub>3</sub> and H<sub>2</sub> monomers within the van der Waals complex and provide an additional tool for evaluating the quality of the NH<sub>3</sub>–H<sub>2</sub> interaction potential. The latter determines the reliability of the calculated excitation and de-excitation rates of ammonia during collisions with hydrogen in the dense interstellar clouds.</div></div>","PeriodicalId":16935,"journal":{"name":"Journal of Quantitative Spectroscopy & Radiative Transfer","volume":"351 ","pages":"Article 109781"},"PeriodicalIF":1.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145657483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号