chan_1993_co2#
W. F. Chan, G. Cooper and C. E. Brion, “The electronic spectrum of carbon dioxide. Discrete and continuum photoabsorption oscillator strengths (6-203 eV)”, Chem. Phys. 178, 401 (1993)
Source record · Catalogue · Review register
DOI: 10.1016/0301-0104(93)85079-n
Source kind: measurement
Recorded technique: Dipole (e,e) spectroscopy. Low resolution (about 1 eV FWHM, 8 keV, zero mean scattering angle): energy-loss spectra at 8.5-39.7, 40-79 and 80-203 eV at about 0.5, 1 and 2 eV intervals, Bethe-Born converted; the valence-shell fraction above 203 eV from a fit A E^-2 + B E^-3 + C E^-4 to 90-203 eV (8.51 %), and the whole TRK-normalised to 16.51 (16 valence electrons plus 0.51 for Pauli-excluded K-shell transitions, from atomic C and O estimates) (pp. 2-3). High resolution (0.048 eV FWHM): 6-30 eV, Bethe-Born converted and normalised at 26 eV to the low-resolution value; the two bands below 10 eV deconvoluted, the others integrated over energy ranges (pp. 7-10). Independent of optical data and target density; no line saturation. Background removed by quartering the sample pressure; energy scale from helium’s 21.218 eV line. Canadian Liquid Air CO2 (p. 3).
Materials in structured entries: CO2
Dataset quantities: differential_oscillator_strength, interval_oscillator_strength, oscillator_strength
Contents: 16 datasets; 1 formula.
Curation notes#
Values per molecule; no density or state involved (room-temperature CO2, not stated). No uncertainty is stated anywhere in the paper for the present values.
Table 1 (p. 5, unlabelled in the extraction): the low-resolution df/dE, 8.53-203.00 eV, 162 points (sigma(Mb) = 109.75 df/dE(eV^-1)); the step changes at 40 and 80 eV (39.74, 40.03; 79.30, 80.05) follow the three measured ranges. Generally good agreement with Samson and Haddad’s photoabsorption; Lee et al. (synchrotron) 5-10 % higher above 22 eV and much lower below; De Reilhac and Damany 10-15 % higher at 37-50 eV and much lower above; Brion and Tan’s (1978) and Hitchcock et al.’s (1980) dipole (e,e) data, normalised to Lee et al., slightly higher (pp. 3-5). Sums computed from Table 1 (2026-09-27; trapezoid from 8.53 eV plus the paper’s A E^-2 + B E^-3 + C E^-4 tail above 203 eV, the formula below): S(0) = 15.020 over 8.53-203 eV and 16.425 in all (normalised to 16.51; the table misses the discrete bands below 8.5 eV and the trapezoid is coarse); S(-1) = 13.384, S(-2) = 16.876 au, S(-3) = 26.63, S(-4) = 47.73, S(-6) = 187.9. Olney et al. (olney_1997 table1_CO2) quote 16.92 au for the S(-2) of ‘the originally published’ spectrum (0.3 % above). The paper prints no S(k).
High resolution (Section 3.2): Table 2 (p. 10; the extraction attaches the caption ‘Table 3’ to it and puts ‘Table 2’ and its caption in its footnotes, a structural fix): the deconvoluted strengths of the two weak diffuse bands below 10 eV, 1Delta_u (peak about 8.38 eV in the table, ‘about 8.35’ in the text) and 1Pi_g (about 9.30 eV; text ‘about 9.40’), with four other measurements. Table 3 (p. 10): the 1Sigma_u+ (1pi_g -> 3p pi_u, about 11.05 eV) and 1Pi_u (1pi_g -> 3p sigma_u, about 11.40 eV) bands, the present values integrated over 10.30-11.28 and 11.28-11.49 eV (interval dataset), with two theories and four experiments per state (the ranges of the others are not stated: band datasets). Table 4 (p. 10): the present oscillator strength integrated over 16 intervals from 11.49 eV to the first ionisation threshold, 13.78 eV. The present intervals 10.30-13.78 eV sum to 1.197, and with the two bands below 10 eV to 1.210 below the IP (checked 2026-09-27).
Text (p. 11): over 14.83-20.66 eV the present estimate is 1.674; the original data of Nakata et al. give 1.372, Berkowitz’s scaled (by 150 %) version 2.031, ‘likely ... overcorrected’ (inline datasets). Figs. 4-6 (6-30, 6-15, 15-20 eV high-resolution spectra) are figures only.
inn_1953 (curated) holds the same three Inn et al. strengths (0.0043, 0.0053, 0.12) as this paper’s Tables 2-3 quote: those datasets are reproduced from inn_1953.
Recorded bibliographic identity status: VALIDATED_WITH_WARNINGS. This concerns identification of the source; it does not establish the scientific correctness of its contents.
Datasets#
chan_1993_co2/continuum#
{
"id": "continuum",
"material": "CO2",
"file": "CO2/chan_1993_co2__continuum.csv",
"table": "tbl_b45cfc94562b",
"quantity": "differential_oscillator_strength",
"unit": "1/eV",
"scale": 0.01,
"abscissa_unit": "eV",
"use": "primary"
}
Table 1: low-resolution (1 eV FWHM) dipole (e,e) absolute df/dE (10^-2 eV^-1), 8.53-203.00 eV, 162 points in print order (about 0.51 eV steps to 39.74 eV, 1.03 eV to 79.30 eV, 2.05 eV to 203 eV); TRK-normalised to 16.51 including the fitted tail above 203 eV (formula tail_fit); independent of optical data. No uncertainty stated.
chan_1993_co2/bands_7_10_present#
{
"id": "bands_7_10_present",
"material": "CO2",
"file": "CO2/chan_1993_co2__bands_7_10_present.csv",
"table": "tbl_914f5351589b",
"quantity": "oscillator_strength",
"abscissa": "label",
"use": "primary"
}
Table 2 ‘present work (HR dipole (e, e))’: deconvoluted oscillator strengths of the two diffuse bands below 10 eV, rows Delta_u (1Delta_u, 1pi_g -> pi*, peak about 8.38 eV) and Pi_g (1Pi_g, 1pi_g -> 3s sigma_g, about 9.30 eV), label abscissa (the peak energies are approximate). Printed in the extraction as ‘Table 3’ (structural; source notes). No uncertainty stated.
chan_1993_co2/bands_7_10_rabalais_1971#
{
"id": "bands_7_10_rabalais_1971",
"material": "CO2",
"file": "CO2/chan_1993_co2__bands_7_10_rabalais_1971.csv",
"table": "tbl_914f5351589b",
"quantity": "oscillator_strength",
"abscissa": "label",
"use": "reproduced",
"reproduced_from": [
"J. W. Rabalais, J. M. McDonald, V. Scherr and S. P. McGlynn, Chem. Rev. 71, 73 (1971)"
]
}
Table 2: oscillator strengths of the 1Delta_u and 1Pi_g bands below 10 eV (rows Delta_u, Pi_g); photoabsorption.
chan_1993_co2/bands_7_10_meyer_1965#
{
"id": "bands_7_10_meyer_1965",
"material": "CO2",
"file": "CO2/chan_1993_co2__bands_7_10_meyer_1965.csv",
"table": "tbl_914f5351589b",
"quantity": "oscillator_strength",
"abscissa": "label",
"use": "reproduced",
"reproduced_from": [
"V. D. Meyer and E. N. Lassettre, J. Chem. Phys. 42, 3436 (1965)"
]
}
Table 2: oscillator strengths of the 1Delta_u and 1Pi_g bands below 10 eV (rows Delta_u, Pi_g); electron impact, generalised oscillator strengths extrapolated to zero momentum transfer, calibrated with helium’s 2 1P line.
chan_1993_co2/bands_7_10_inn_1953#
{
"id": "bands_7_10_inn_1953",
"material": "CO2",
"file": "CO2/chan_1993_co2__bands_7_10_inn_1953.csv",
"table": "tbl_914f5351589b",
"quantity": "oscillator_strength",
"abscissa": "label",
"use": "reproduced",
"reproduced_from": [
"inn_1953"
]
}
Table 2: oscillator strengths of the 1Delta_u and 1Pi_g bands below 10 eV (rows Delta_u, Pi_g); photoabsorption; the same values as inn_1953’s continuum_f (0.0043, 0.0053, 0.12; agreement exact).
chan_1993_co2/bands_7_10_wilkinson_1950#
{
"id": "bands_7_10_wilkinson_1950",
"material": "CO2",
"file": "CO2/chan_1993_co2__bands_7_10_wilkinson_1950.csv",
"table": "tbl_914f5351589b",
"quantity": "oscillator_strength",
"abscissa": "label",
"use": "reproduced",
"reproduced_from": [
"P. G. Wilkinson and H. L. Johnston, J. Chem. Phys. 18, 190 (1950)"
]
}
Table 2: oscillator strengths of the 1Delta_u and 1Pi_g bands below 10 eV (rows Delta_u, Pi_g); photoabsorption.
chan_1993_co2/intervals_present#
{
"id": "intervals_present",
"material": "CO2",
"file": "CO2/chan_1993_co2__intervals_present.csv",
"table": "tbl_ae9d1bb0325b, tbl_c908d6e74402",
"quantity": "interval_oscillator_strength",
"abscissa_unit": "eV",
"columns": {
"x_upper": "eV"
},
"use": "primary"
}
Tables 3 and 4 ‘present work’: the high-resolution (0.048 eV) oscillator strength integrated over 10.30-11.28 eV (the 1Sigma_u+ band, 0.171) and 11.28-11.49 eV (the 1Pi_u band, 0.0603) (Table 3) and over 16 intervals from 11.49 eV to the first ionisation threshold, 13.78 eV (Table 4); row = the range, x and x_upper its edges. Contiguous; they sum to 1.197. No uncertainty stated.
chan_1993_co2/bands_10_11_padial_1981#
{
"id": "bands_10_11_padial_1981",
"material": "CO2",
"file": "CO2/chan_1993_co2__bands_10_11_padial_1981.csv",
"table": "tbl_ae9d1bb0325b",
"quantity": "oscillator_strength",
"abscissa": "label",
"use": "reproduced",
"reproduced_from": [
"N. Padial, G. Csanak, B. V. McKoy and P. W. Langhoff, Phys. Rev. A 23, 218 (1981)"
]
}
Table 3: oscillator strengths of the 1Sigma_u+ (about 11.05 eV) and 1Pi_u (about 11.40 eV) bands, rows Sigma_u and Pi_u (the integration ranges are the present work’s; the source’s own are not stated); theory, Stieltjes-Tchebycheff, separated-channel static exchange.
chan_1993_co2/bands_10_11_mccurdy_1974#
{
"id": "bands_10_11_mccurdy_1974",
"material": "CO2",
"file": "CO2/chan_1993_co2__bands_10_11_mccurdy_1974.csv",
"table": "tbl_ae9d1bb0325b",
"quantity": "oscillator_strength",
"abscissa": "label",
"use": "reproduced",
"reproduced_from": [
"C. W. McCurdy and V. McKoy, J. Chem. Phys. 61, 2820 (1974)"
]
}
Table 3: oscillator strengths of the 1Sigma_u+ (about 11.05 eV) and 1Pi_u (about 11.40 eV) bands, rows Sigma_u and Pi_u (the integration ranges are the present work’s; the source’s own are not stated); theory, equations of motion.
chan_1993_co2/bands_10_11_klump_1978#
{
"id": "bands_10_11_klump_1978",
"material": "CO2",
"file": "CO2/chan_1993_co2__bands_10_11_klump_1978.csv",
"table": "tbl_ae9d1bb0325b",
"quantity": "oscillator_strength",
"abscissa": "label",
"use": "reproduced",
"reproduced_from": [
"K. N. Klump and E. N. Lassettre, J. Electron Spectrosc. Relat. Phenom. 14, 215 (1978)"
]
}
Table 3: oscillator strengths of the 1Sigma_u+ (about 11.05 eV) and 1Pi_u (about 11.40 eV) bands, rows Sigma_u and Pi_u (the integration ranges are the present work’s; the source’s own are not stated); electron impact, generalised oscillator strengths normalised to Bromberg’s elastic cross sections; about 25 % below the present values (p. 9).
chan_1993_co2/bands_10_11_rabalais_1971#
{
"id": "bands_10_11_rabalais_1971",
"material": "CO2",
"file": "CO2/chan_1993_co2__bands_10_11_rabalais_1971.csv",
"table": "tbl_ae9d1bb0325b",
"quantity": "oscillator_strength",
"abscissa": "label",
"use": "reproduced",
"reproduced_from": [
"J. W. Rabalais, J. M. McDonald, V. Scherr and S. P. McGlynn, Chem. Rev. 71, 73 (1971)"
]
}
Table 3: oscillator strengths of the 1Sigma_u+ (about 11.05 eV) and 1Pi_u (about 11.40 eV) bands, rows Sigma_u and Pi_u (the integration ranges are the present work’s; the source’s own are not stated); photoabsorption.
chan_1993_co2/bands_10_11_meyer_1965#
{
"id": "bands_10_11_meyer_1965",
"material": "CO2",
"file": "CO2/chan_1993_co2__bands_10_11_meyer_1965.csv",
"table": "tbl_ae9d1bb0325b",
"quantity": "oscillator_strength",
"abscissa": "label",
"use": "reproduced",
"reproduced_from": [
"V. D. Meyer and E. N. Lassettre, J. Chem. Phys. 42, 3436 (1965)"
]
}
Table 3: oscillator strengths of the 1Sigma_u+ (about 11.05 eV) and 1Pi_u (about 11.40 eV) bands, rows Sigma_u and Pi_u (the integration ranges are the present work’s; the source’s own are not stated); electron impact, generalised oscillator strengths extrapolated to zero momentum transfer, calibrated with helium’s 2 1P line. Their 1Sigma_u+ value agrees with the present one; their 1Pi_u value is about 20 % higher (p. 10).
chan_1993_co2/bands_10_11_inn_1953#
{
"id": "bands_10_11_inn_1953",
"material": "CO2",
"file": "CO2/chan_1993_co2__bands_10_11_inn_1953.csv",
"table": "tbl_ae9d1bb0325b",
"quantity": "oscillator_strength",
"abscissa": "label",
"use": "reproduced",
"reproduced_from": [
"inn_1953"
]
}
Table 3: oscillator strengths of the 1Sigma_u+ (about 11.05 eV) and 1Pi_u (about 11.40 eV) bands, rows Sigma_u and Pi_u (the integration ranges are the present work’s; the source’s own are not stated); photoabsorption; the same values as inn_1953’s continuum_f (0.0043, 0.0053, 0.12; agreement exact).
chan_1993_co2/interval_15_21_present#
{
"id": "interval_15_21_present",
"material": "CO2",
"table": "text",
"quantity": "interval_oscillator_strength",
"abscissa_unit": "eV",
"columns": {
"x_upper": "eV"
},
"use": "check"
}
1 inline points in the source record.
p. 11: ‘the present estimate’ of the oscillator strength over 14.83-20.66 eV, 1.674 (an integral of the present spectra; the low-resolution Table 1 gives about 1.82 over 14.67-20.81 eV). A check.
chan_1993_co2/interval_15_21_nakata#
{
"id": "interval_15_21_nakata",
"material": "CO2",
"table": "text",
"quantity": "interval_oscillator_strength",
"abscissa_unit": "eV",
"columns": {
"x_upper": "eV"
},
"use": "reproduced",
"reproduced_from": [
"R. S. Nakata, K. Watanabe and F. M. Matsunaga, Sci. Light 14, 54 (1965)"
]
}
1 inline points in the source record.
p. 11: ‘Integration of the original data reported by Nakata et al. [4] in the 14.83-20.66 eV energy region gives an oscillator strength of 1.372’, about 20 % below the present value (Chan et al.’s integration).
chan_1993_co2/interval_15_21_berkowitz#
{
"id": "interval_15_21_berkowitz",
"material": "CO2",
"table": "text",
"quantity": "interval_oscillator_strength",
"abscissa_unit": "eV",
"columns": {
"x_upper": "eV"
},
"use": "reproduced",
"reproduced_from": [
"J. Berkowitz, Photoabsorption, Photoionization and Photoelectron Spectroscopy (Academic Press, New York, 1979), p. 119",
"R. S. Nakata, K. Watanabe and F. M. Matsunaga, Sci. Light 14, 54 (1965)"
]
}
1 inline points in the source record.
p. 11: Berkowitz scaled Nakata et al.’s data by 150 % over 14.83-20.66 eV (their data being about 50 % below Cairns and Samson’s at 18.23-21.37 eV), which gives 2.031, about 20 % above the present value: ‘likely that Berkowitz ... overcorrected’.
Formulas#
chan_1993_co2/tail_fit#
{
"id": "tail_fit",
"material": "CO2",
"equation": "Section 3.1, p. 3",
"printed": "df/dE = A E^-2 + B E^-3 + C E^-4, fitted over 90-203 eV: 'A = 2.616, B = 95.24 and C = 246.9 (x10^4)'",
"variable": "E: photon energy in eV; df/dE (in Table 1's unit, 10^-2 eV^-1) = factor x (A E^-2 + B E^-3 + C E^-4), the printed '(x10^4)' read as applying to all three coefficients",
"state": "none (per molecule)",
"density": "none",
"range": "fitted over 90-203 eV; used to estimate the valence-shell oscillator strength above 203 eV (8.51 % of 16.51)",
"coefficients": {
"A": "2.616",
"B": "95.24",
"C": "246.9",
"factor": "1e4"
},
"check": "Read with every coefficient times 10^4 and df/dE in 10^-2 eV^-1: the integral from 203 eV to infinity is 1.4052, 8.511 % of 16.51 (printed 8.51 %); the curve gives 0.750 at 203.00 eV and 3.549 at 100.54 eV against Table 1's 0.788 and 3.58 (computed 2026-09-27). The '(x10^4)' is printed after C only; applying it to C alone gives nothing sensible (A/E^2 = 6e-5 at 203 eV)."
}
The paper’s high-energy extrapolation of the low-resolution df/dE (Fig. 1 insert shows it to 300 eV). The scale factor 10^4 applied to all three coefficients and the unit 10^-2 eV^-1 are inferred from the check; the coefficients are as printed, the factor separate.
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.