scholarly journals An update to the MARVEL data set and ExoMol line list for 12C2

2020 ◽  
Vol 497 (1) ◽  
pp. 1081-1097 ◽  
Author(s):  
Laura K McKemmish ◽  
Anna-Maree Syme ◽  
Jasmin Borsovszky ◽  
Sergei N Yurchenko ◽  
Jonathan Tennyson ◽  
...  

ABSTRACT The spectrum of dicarbon (C2) is important in astrophysics and for spectroscopic studies of plasmas and flames. The C2 spectrum is characterized by many band systems with new ones still being actively identified; astronomical observations involve eight of these bands. Recently, Furtenbacher et al. presented a set of 5699 empirical energy levels for 12C2, distributed among 11 electronic states and 98 vibronic bands, derived from 42 experimental studies and obtained using the MARVEL (Measured Active Rotational-Vibrational Energy Levels) procedure. Here, we add data from 13 new sources and update data from 5 sources. Many of these data sources characterize high-lying electronic states, including the newly detected 3 3Πg state. Older studies have been included following improvements in the MARVEL procedure that allow their uncertainties to be estimated. These older works in particular determine levels in the C 1Πg state, the upper state of the insufficiently characterized Deslandres–d’Azambuja (C 1Πg–A 1Πu) band. The new compilation considers a total of 31 323 transitions and derives 7047 empirical (marvel) energy levels spanning 20 electronic and 142 vibronic states. These new empirical energy levels are used here to update the 8states C2 ExoMol line list. This updated line list is highly suitable for high-resolution cross-correlation studies in astronomical spectroscopy of, for example, exoplanets, as 99.4 per cent of the transitions with intensities over 10−18 cm molecule−1 at 1000 K have frequencies determined by empirical energy levels.

Author(s):  
Charles A Bowesman ◽  
Meiyin Shuai ◽  
Sergei N Yurchenko ◽  
Jonathan Tennyson

Abstract Indications of aluminium monoxide in atmospheres of exoplanets are being reported. Studies using high resolution spectroscopy should allow a strong detection but require high accuracy laboratory data. A Marvel (measured active rotational-vibrational energy levels) analysis is performed for the available spectroscopic data on 27Al16O: 22 473 validated transitions are used to determine 6 485 distinct energy levels. These empirical energy levels are used to provide an improved, spectroscopically accurate version of the ExoMol ATP line list for 27Al16O; at the same time the accuracy of the line lists for the isotopically-substituted species 26Al16O, 27Al17O and 27Al18O are improved by correcting levels in line with the corrections used for 27Al16O. These line lists are available from the ExoMol database at http://www.exomol.com.


2020 ◽  
Vol 499 (1) ◽  
pp. 25-39
Author(s):  
Anna-Maree Syme ◽  
Laura K McKemmish

ABSTRACT The cyano radical (CN) is a key molecule across many different factions of astronomy and chemistry. Accurate, empirical rovibronic energy levels with uncertainties are determined for eight doublet states of CN using the marvel (Measured Active Rotational-Vibrational Energy Levels) algorithm. 40 333 transitions were validated from 22 different published sources to generate 8083 spin-rovibronic energy levels. The empirical energy levels obtained from the marvel analysis are compared to current energy levels from the mollist line list. The mollist transition frequencies are updated with marvel energy level data which brings the frequencies obtained through experimental data up to 77.3 per cent from the original 11.3 per cent, with 92.6 per cent of the transitions with intensities over 10−23 cm molecule−1 at 1000 K now known from experimental data. At 2000 K, 100.0 per cent of the partition function is recovered using only marvel energy levels, while 98.2 per cent is still recovered at 5000 K.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Liu Sun ◽  
Li Zhao ◽  
Rui-Yun Peng

AbstractWith the rapid development of terahertz technologies, basic research and applications of terahertz waves in biomedicine have attracted increasing attention. The rotation and vibrational energy levels of biomacromolecules fall in the energy range of terahertz waves; thus, terahertz waves might interact with biomacromolecules. Therefore, terahertz waves have been widely applied to explore features of the terahertz spectrum of biomacromolecules. However, the effects of terahertz waves on biomacromolecules are largely unexplored. Although some progress has been reported, there are still numerous technical barriers to clarifying the relation between terahertz waves and biomacromolecules and to realizing the accurate regulation of biological macromolecules by terahertz waves. Therefore, further investigations should be conducted in the future. In this paper, we reviewed terahertz waves and their biomedical research advantages, applications of terahertz waves on biomacromolecules and the effects of terahertz waves on biomacromolecules. These findings will provide novel ideas and methods for the research and application of terahertz waves in the biomedical field.


2007 ◽  
Vol 245 (2) ◽  
pp. 115-125 ◽  
Author(s):  
Tibor Furtenbacher ◽  
Attila G. Császár ◽  
Jonathan Tennyson

RSC Advances ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 3613-3621
Author(s):  
Yonghong Xu ◽  
Huihui Wang ◽  
Yonggang Yang ◽  
Changyong Li ◽  
Liantuan Xiao ◽  
...  

The band structures of the vibrational energy levels of B11− lead to corresponding spectral broadening. The vibrational band-structures of planar boron rotors are caused by internal rotations.


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