bethke_1959#
G. W. Bethke, “Oscillator strengths in the far ultraviolet. II. Oxygen Schumann-Runge bands”, J. Chem. Phys. 31, 669 (1959)
Source record · Catalogue · Review register
DOI: 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#
{
"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#
{
"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#
{
"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#
{
"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 review register for the checks and decisions.