J/A+A/595/A130ivo://CDS.VizieR/J/A+A/595/A130doi:10.26093/cds/vizier.35950130CDSPopovas A.Jorgensen U.G.2016-11-16T07:45:10Z2016-11-16T08:44:27ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.fratomic-physicsHydrogen is the most abundant molecule in the Universe. Its thermodynamic quantities dominate the physical conditions in molecular clouds, protoplanetary disks, etc. It is also of high interest in plasma physics. Therefore thermodynamic data for molecular hydrogen have to be as accurate as possible in a wide temperature range. We here rigorously show the shortcomings of various simplifications that are used to calculate the total internal partition function. These shortcomings can lead to errors of up to 40 percent or more in the estimated partition function. These errors carry on to calculations of thermodynamic quantities. Therefore a more complicated approach has to be taken. Seven possible simplifications of various complexity are described, together with advantages and disadvantages of direct summation of experimental values. These were compared to what we consider the most accurate and most complete treatment (case 8). Dunham coefficients were determined from experimental and theoretical energy levels of a number of electronically excited states of H2. Both equilibrium and normal hydrogen was taken into consideration.2016A&A...595A.130Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/595/A130CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/595/A130https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/595/A130http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/595/A130https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/595/A130https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/595/A130http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/595/A130GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/A+A/595/A130/h2normalPartition function and thermodynamic quantities for normal H_2_ in 1K temperature steps, ranging 1-20000KrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTTemperatureKphys.temperaturefloatQPartition functionphys.atmoldoubleEint/RTInternal contribution to the thermodynamic energyJphys.energydoubleH-H(0)EnthalpyJ/molphys.atmoldoubleSEntropyJ.K**-1.molphys.atmoldoubleCpConstant-pressure specific heatJ.K**-1.molphys.atmoldoubleCvConstant-volume specific heatJ.K**-1.molphys.atmoldouble[-G-H(0)]/TGibbs free energyJ.K**-1.molphys.energy;phys.atmol.leveldoublegammaAdiabatic indexphys.atmoldoubleJ/A+A/595/A130/h2orthoPartition function and thermodynamic quantities for ortho-H_2_ in 1K temperature steps, ranging 1-20000KTTemperatureKphys.temperaturefloatQPartition functionphys.atmoldoublerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintEint/RTInternal contribution to the thermodynamic energyJphys.energydoubleH-H(0)EnthalpyJ/molphys.atmoldoubleSEntropyJ.K**-1.molphys.atmoldoubleCpConstant-pressure specific heatJ.K**-1.molphys.atmoldoubleCvConstant-volume specific heatJ.K**-1.molphys.atmoldouble[-G-H(0)]/TGibbs free energyJ.K**-1.molphys.energy;phys.atmol.leveldoublegammaAdiabatic indexphys.atmoldoubleJ/A+A/595/A130/h2equilPartition function and thermodynamic quantities for equilibrium H_2_ in 1K temperature steps, ranging 1-20000KrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTTemperatureKphys.temperaturefloatQPartition functionphys.atmoldoubleEint/RTInternal contribution to the thermodynamic energyJphys.energydoubleH-H(0)EnthalpyJ/molphys.atmoldoubleSEntropyJ.K**-1.molphys.atmoldoubleCpConstant-pressure specific heatJ.K**-1.molphys.atmoldoubleCvConstant-volume specific heatJ.K**-1.molphys.atmoldouble[-G-H(0)]/TGibbs free energyJ.K**-1.molphys.energy;phys.atmol.leveldoublegammaAdiabatic indexphys.atmoldoubleJ/A+A/595/A130/h2paraPartition function and thermodynamic quantities for para-H_2_ in 1K temperature steps, ranging 1-20000KTTemperatureKphys.temperaturefloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintQPartition functionphys.atmoldoubleEint/RTInternal contribution to the thermodynamic energyJphys.energydoubleH-H(0)EnthalpyJ/molphys.atmoldoubleSEntropyJ.K**-1.molphys.atmoldoubleCpConstant-pressure specific heatJ.K**-1.molphys.atmoldoubleCvConstant-volume specific heatJ.K**-1.molphys.atmoldouble[-G-H(0)]/TGibbs free energyJ.K**-1.molphys.energy;phys.atmol.leveldoublegammaAdiabatic indexphys.atmoldouble