bethke_1959
===========

G\. W\. Bethke, "Oscillator strengths in the far ultraviolet\. II\. Oxygen Schumann\-Runge bands", J\. Chem\. Phys\. 31, 669 \(1959\)

`Source record <https://github.com/LupoLab/optmat/blob/main/src/optmat/data/sources/bethke_1959.toml>`__ · :doc:`Catalogue </the-data/sources>` · :doc:`Review register </register>`

DOI: `10\.1063/1\.1730444 <https://doi.org/10.1063/1.1730444>`__

**Source kind:** measurement

**Recorded technique:** Photoelectric absorption of pressure\-broadened O2 spectra, 1750\-2000 A\: grating vacuum\-ultraviolet spectrometer \(resolution about 0\.4 A\), stabilised hydrogen discharge, sodium\-salicylate phosphor and photomultiplier; a 0\.702 cm \(\+\-2 %\) cell with fused\-silica windows; O2 \(99\.6 %, distilled below 1 atm\) broadened by argon to 0\-1975 psia, O2 partial pressures giving 20\-50 % peak absorption \(p\. 669\)\. Band intensities planimetered between vertical lines through the transmission maxima nearest each head \(Fig\. 1\); K extrapolated from the straight high\-pressure part of K against total pressure to zero total pressure \(K\_0, Fig\. 3\); for v' \< 11 also extrapolated to zero O2 pressure to remove the O4 continuum \(p\. 670\)\.

**Materials in structured entries:** O2

**Dataset quantities:** oscillator\_strength

**Contents:** 4 datasets; 0 formulas.

Curation notes
--------------

Journal pages 669\-673 = PDF pages 2\-6 \(page 1 is the publisher's cover\)\. O2 only\. Values per molecule, from the ground vibrational level \(bands \(v', 0\)\); the temperature is not stated \(room temperature; F\(v''\) is the vibrational fraction\)\.

Table I \(image checked\)\: K\_0 = integral k\_nu dnu \(cm^\-2 atm^\-1, nu in cm^\-1, P the O2 partial pressure in atmospheres at 0 C, Eq\. 1\) and f\(v', v''\) = \(m c^2 / \(pi e^2 N\_0\)\) K\_0 / F\(v''\) = 4\.203e\-8 K\_0 / F\(v''\) \(Eq\. 2, N\_0 the number density at 1 atm and 0 C\)\. Check \(2026\-09\-25\)\: 4\.203e\-8 K\_0 reproduces every printed f within the rounding of K\_0 \(at most 0\.2 %; F\(v'' = 0\) = 1 to this precision\); the bands and the remainder sum to 31\.38e\-5 against the printed total 31\.4e\-5, the K\_0 to 7468\.6 against 7469\. K\_0 is not extracted \(no vocabulary quantity; f carries the same information\)\.

Accuracy \(p\. 671\)\: 'The values of K\_0 and f\(v', v''\) given in Table I are all accurate to within about \+\-8 % except for the very weak \(4, 0\), \(3, 0\), and \(2, 0\) bands which are accurate to about \+\-12 %, \+\-18 %, and \+\-30 %, respectively\. Overlapping errors are not included'; overlap makes the band values 'increasingly too large as v' is increased until at about v' = 13 the intensities become decreasingly too large and then too small as v' approaches twenty', negligible below v' = 8; the total is not affected\. The bands also include the weak X 3Sigma\_g^\- \-\> 3Pi\_u continuum of Wilkinson and Mulliken \(about 15 % of the absorption near 1781\-1796 A, where they measured k = 0\.44 and 0\.28 cm^\-1\), not subtracted\: 'the true f\(v', 0\) sum for the S\-R band system is probably between 0\.00027 and 0\.00031 \(\+\-8 %\)' against the observed 0\.000314 \+\- 8 % \(all absorption above the dissociation limit 1750\.46 A\) \(p\. 671\)\.

Not extracted\: q\(v', v''\) \(Franck\-Condon factors reproduced from Jarmain, Fraser and Nicholls 1955\) and f\(v', v''\)\_el \(the electronic oscillator strength derived from each band with q and nu\-bar = 68 380 cm^\-1, Eqs\. 3\-5\), whose extrapolation to v' = 0 gives f\_el = 0\.163 \+\- 10 % \(p\. 673\), for r = 1\.37 A\. The continuum oscillator strengths quoted \(p\. 673\)\: Ladenburg and Van Voorhis 0\.193, Ditchburn and Heddle 0\.215 \+\- 0\.02 \(plus 0\.0445 for their band sum\), Watanabe et al\. 0\.161 \(watanabe\_1953\); Wilkinson and Mulliken's 3Pi\_u f\_el about 0\.01\.

Ditchburn and Heddle's band strengths \(column six, Proc\. Roy\. Soc\. A 226, 509 \(1954\)\) are 80 to 110 times larger than these for \(2,0\)\-\(8,0\) and their sum \(0\.0445\) 140 times \(p\. 671\); Matsui et al\. \(2003, matsui\_2003\) find \(12,0\)\-\(17,0\) 15\-28 % below this work\. Wavelengths of the bands are not tabulated \(the abscissa is the index v'\)\.

**Recorded bibliographic identity status:** VALIDATED\_WITH\_WARNINGS. This concerns identification of the source; it does not establish the scientific correctness of its contents.

Datasets
--------

bethke\_1959/band\_f
~~~~~~~~~~~~~~~~~~~~

.. code-block:: text

   {
     "id": "band_f",
     "material": "O2",
     "file": "O2/bethke_1959__band_f.csv",
     "table": "tbl_172bb90e7da2",
     "quantity": "oscillator_strength",
     "scale": 1e-05,
     "abscissa": "label",
     "use": "primary",
     "uncertainty": {
       "relative": 0.08,
       "level": "not stated",
       "relative_rows": {
         "(4,0)": 0.12,
         "(3,0)": 0.18,
         "(2,0)": 0.3
       }
     }
   }

Table I column f\(v', v''\)\: the absorption oscillator strengths of the Schumann\-Runge bands \(v', 0\), v' = 2\-17 \(index v'\), in units of 1e\-5 \(the printed '\(\-5\)'\)\. \+\-8 %, \(4,0\) 12 %, \(3,0\) 18 %, \(2,0\) 30 % \(level not stated\); band\-overlap errors, significant above v' = 8, are not included, and the weak 3Pi\_u continuum \(up to 15 % near 1780\-1800 A\) is not subtracted\. The \(9,0\) value is printed 1\.07 with a subscript guard digit 1\.

bethke\_1959/remainder
~~~~~~~~~~~~~~~~~~~~~~

.. code-block:: text

   {
     "id": "remainder",
     "material": "O2",
     "file": "O2/bethke_1959__remainder.csv",
     "table": "tbl_172bb90e7da2",
     "quantity": "oscillator_strength",
     "scale": 1e-05,
     "abscissa": "label",
     "use": "primary",
     "uncertainty": {
       "relative": 0.08,
       "level": "not stated"
     }
   }

Table I row 'Remainder' \(note d\)\: the summed oscillator strength of the band system beyond \(17,0\) to the dissociation limit \(1750\.46 A\), i\.e\. v' \>= 18; index 18 marks its first band\. Unresolved overlapping bands\. \+\-8 % \(level not stated\)\.

bethke\_1959/total
~~~~~~~~~~~~~~~~~~

.. code-block:: text

   {
     "id": "total",
     "material": "O2",
     "file": "O2/bethke_1959__total.csv",
     "table": "tbl_172bb90e7da2",
     "quantity": "oscillator_strength",
     "scale": 1e-05,
     "abscissa": "label",
     "use": "check",
     "uncertainty": {
       "relative": 0.08,
       "level": "not stated"
     }
   }

Table I row 'Total'\: 31\.4e\-5, the whole Schumann\-Runge band system above 1750\.46 A \(bands \(2,0\)\-\(17,0\) and the remainder; index 2, its first band\)\. The sum of band\_f and remainder\: a check\. The text \(p\. 671\) puts the true band sum at 0\.00027\-0\.00031 once the underlying 3Pi\_u continuum is allowed for\.

bethke\_1959/ditchburn\_heddle
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

.. code-block:: text

   {
     "id": "ditchburn_heddle",
     "material": "O2",
     "file": "O2/bethke_1959__ditchburn_heddle.csv",
     "table": "tbl_172bb90e7da2",
     "quantity": "oscillator_strength",
     "scale": 1e-05,
     "abscissa": "label",
     "use": "excluded",
     "reproduced_from": [
       "ditchburn_1954"
     ]
   }

Table I column six \(note b\)\: Ditchburn and Heddle's band oscillator strengths \(v', 0\), v' = 2\-17, from photographic spectra without pressure broadening, reproduced for comparison; 80\-110 times this work's values for \(2,0\)\-\(8,0\) and not consistent with f\_el \(0\.8 to 16 from them against 0\.030\-0\.55 expected, p\. 669\)\. Their 'Remainder' 2276e\-5 \(note e\: f\(18,0\)\+f\(19,0\)\+f\(20,0\) extrapolated\) and total 4450e\-5 are not extracted\. Excluded\: kept for the record, not usable \(Bethke's own verdict and Matsui et al\.'s values\)\.

Formulas
--------

No formulas are recorded.

Corrections
-----------

No dataset errata are recorded in this source record.

Formula corrections, where recorded, appear with their formulas above. Curation notes may also discuss corrections or unresolved interpretation. Consult the :doc:`review register </register>` for the checks and decisions.