69 th international symposium on molecular spectroscopy / champaign-urbana, illinois, usa, june...

69th International Symposium on Molecular Spectroscopy / Champaign-Urbana, Illinois, USA, June 16–20, 2014

CH4, C2H4, SF6 AND CF4 CALCULATED SPECTROSCOPIC DATABASES FOR THE

VIRTUAL ATOMIC AND MOLECULAR DATA CENTRE

V. BOUDON, Ch. WENGER, R. SURLEAU, M. LOUVIOT, M. FAYE, Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-Université de Bourgogne, 9. Av. A. Savary, BP 47870, F-21078 Dijon Cedex, France

M. ROTGER, L. DAUMONT, D. A. BONHOMMEAU, Vl. G. TYUTEREV, Groupe de Spectrométrie Moléculaire et Atmosphérique (GSMA), CNRS UMR7 331, Université de Reims Champagne-Ardenne, Moulin de la Housse, B.P.1039, F-51687 Reims Cedex 2, France

Y. A. BA, M.-L. DUBERNET, LERMA2, CNRS UMR8812, Observatoire de Paris, 5 Place Janssen, 92195 Meudon

LERMA2


Contents

I. Virtual Atomic and Molecular Data Centre

II. Methane, CH4

III. Ethylene, C2H4

IV. Sulfur hexafluoride, SF6 & Carbon tetrafluoride, CF4

V. Conclusion and perspectives


I. Virtual Atomic and Molecular Data Centre


Dadabases

Line list construction for HITRAN and GEISA

(with Linda Brown, determination of semi-empirical upper states)

Dijon spectroscopic analyses and databasesExperimental data

Global modelling

SPVIEW interface

FP7 – Research Infrastructures

Globale-Infrastructure

• European project• Global portal• « Modern » database• Data traceability

In Dijon :Server with calculated CH4 lines

Fits and calculations

XTDS interface

Line lists

Positions, intensities, collisional parameters, accuracy

Since 2012 : OSU « THETA »Terre-Homme-Environnement-Temps-

Astronomie


Virtual Atomic and Molecular Data Centre

The Dijon group hosts 3 databases on a dedicated server:• MeCaSDa (CH4)

• SHeCaSDa (SF6)

• TFMeCaSDa (CF4)The Reims group hosts 2 databases on a dedicated server:• ECaSDa (C2H4)

• S&MPO (O3)


Relational database (simplified) schema

Main ideas:• Store states• Transitions refer

to upper and lower state IDs


MeCaSDa construction & languages• Database developped from scratch.

• Database structure based on existing XSAMS schema (IAEA’s XML Schema for Atomic, Molecular and Solid data), adapted to requests.

• XSAMS was modified for specific methane requirements.

• Fortran programs for data calculation, extraction and SQL table loading.

• The database is re-created each time data are updated (non-interactive).

• MySQL database.

• Node software written in Python under Django framework. Used to make correspondance with the XSAMS schema.

• Some Python development was needed for data extraction by requests.FORTRAN


Query through the VAMDC portal

http://portal.vamdc.org

Search into multiple databases


II. Methane, CH4

MeCaSDa: Methane Calculated Spectroscopic Database


Direct access to MeCaSDa


Methane’s complex spectrum

12C

H4 g

loba

l fit

13

13

13 13

13


Present status of line-by-line analyses (12CH4)

Polyad / Spectral region Positions Intensities Profiles

1 – Ground state0–200 cm-1 (> 5.0 μm)

Complete analysis,J ≤ 24

Complete analysisPerturber:

N2

2 – Dyad1000–1800 cm-1 (5.6–10.0 μm)


Complete analysis,+ some hot bands

Perturbers:He et N2

3 – Pentad2200–3300 cm-1 (3.0–4.6 μm)


Complete analysis (cold bands)

Perturbers:He, Ar, N2, O2, CH4

4 – Octad3700–4800 cm-1 (2.0–2.7 μm)

Very good analysis,J ≤ 21

Very good analysis, (cold bands)

Perturbers:N2

5 – Tetradecad5400–6300 cm-1 (1.6–1.9 μm)

Satisfying analysis,J ≤ 15

Satisfying analysis (cold bands)

No calculation

6 – Icosad6600–7700 cm-1 (1.3 – 1.5 μm)

Very partial analysis(3 band among 20)

No analysis No calculation

Upper polyads> 7800 cm-1 (< 1.28 μm)

No analysis No analysis No calculation

Windows(polyad far wings, all regions)

No analysis No analysis No calculation


States and transitions in MeCaSDa12CH4/13CH4 Vib. levels Vib. sublevels Maximum J Rovib. states

P0 – GS 1 1 25/25 282/282

P1 – Dyad 2 2 25/25 1408/1408

P2 – Pentad 5 9 25/25 5352/5352

P3 – Octad 8 26 22/12 12142/3874

P4 – Tetradecad 14 60 17/0 18900/0


Methane absorption lines in MeCaSDa


Methane Raman lines in MeCaSDa


III. Ethylene, C2H4

ECaSDa: Ethylene Calculated Spectroscopic Database


Present status of analyses

ν4/ν7/ν10/ν12 tetrad:

• Global analysis • To be published soon• Positions & intensities

1.6 and 3 μm:

Preliminary analysis


States and transitions in ECaSDa

12C2H4 Vib. levels Vib. sublevels Maximum J

Rovib. states

Scheme 1

P0 – GS 1 1 45 2116

P1 – ν4/ν7/ν10/ν12 4 4 45 8464

Scheme 2

P0 – GS 1 1 36 1369

P1 – ν5 1 1 35 1296

P2 – ν9/ν11 2 2 35 2592

P3 – ν5+ν9/ν5+ν11 2 2 35 2592


IV. Sulfur hexafluoride, SF6 & Carbon tetrafluoride, CF4

SHeCaSDa: Sulfur Hexafluoride Calculated Spectroscopic Database

TFMeCaSDa:Tetra-Fluoro-Methane Calculated Spectroscopic Database


Present status of analyses for SF6• SF6 absolute intensities is a difficult problem • At present, the database only contains ν3–ν1, ν3–ν2, ν3, ν4 and

ν4+ν6–ν6, ν2+ν3, 3ν3

• Global fits of levels implying ν1, ν2, ν3 their combinations and overtones are undeway

• Only 32 % of the molecules in the ground state at 293 K

• Need to analyze hot bands to correctly model atmospheric absorption


Present status and analyses for CF4

RAMANBoudon et al., J. Raman Spectrosc. 44, 731–738 (2013)

2ν1–ν1

Global

analy

sis

INFRAREDBoudon et al., Mol. Phys. 109, 2273–2290 (2011)

Global analysis

This is in HITRAN

Coriolis

Collaboration with C. Maul

Goal :

Analyze all lower states in order to understand the hot bands in the ν3 region

(65 % of CF4 in GS at room T).


States and transitions


V. Conclusions and perspectives


Future developments

Spectroscopic analyses:

• Continue the global fit approach

• Hot methane (combustions, brown dwarfs, exoplanets, … )

• Towards higher excited states of ethylene

• Hot bands of SF6 and CF4

Database improvements:

• We look for another optimized SQL engine

• PostgreSQL could be a solution


The SMPCA Group in Dijon

Molecular Spectroscopy, Collisional Processes and Applications

69 th international symposium on molecular spectroscopy / champaign-urbana, illinois, usa, june...

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molecular data centre

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