Table Of Contents

Absorption cross-sections

Among with RadiativeTransition elements, Radiative processes block now has a CrossSection element, which allows description of absorption cross-section data and vibrational bands assignment in case of complex molecules.

RadiativeTransition child elements
  • Description, X and Y elements describe cross-section data in tabular form, where X can be absorbed radiation frequency, wavelength or wavenumber in a form of a list of values or sequence. Y then represents a sequence of sigma values.
  • Species element may have StateRef and/or SpeciesRef child elements, indicating species or specific states, to which crossection data applies.
  • BandAssignment allows to indicate specific vibrational modes in cross-section data.
CrossSection BandAssignment element

Example cross-sections record

Warning: DataList is truncated for clarity, originally it contains 880 space-separated numbers. You may see the original element in schema examples (tests/valid/azulene-working.xml).


        <Description>The IR transmittance cross section of azulene from the NIST
        Standard Reference Data Program Collection</Description>

        <X parameter="wavenumber" units="1/cm">
                <LinearSequence n="880" units="1/cm" a0="450." a1="4"/>
        <Y parameter="sigma" units="arbitrary">
                <DataList n="880">
                        0 85 94 .. 102


        <BandAssignment name="2v1+v2">
                        <Value units="1/cm">410</Value>
                        <Value units="1/cm">40</Value>
                        <DeltaV modeID="V1">2</DeltaV>
                        <DeltaV modeID="V2">1</DeltaV>
        <BandAssignment name="3v4+2v5">
                        <Value units="1/cm">1657</Value>
                        <Value units="1/cm">120</Value>
                        <DeltaV modeID="V2">3</DeltaV>
                        <DeltaV modeID="V3">2</DeltaV>