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 `__ · :doc:`Catalogue ` · :doc:`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 ~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "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 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "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 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "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 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "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 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "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 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "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 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "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 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "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 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "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 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "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 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "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 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "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 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "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 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "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 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "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 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "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 ~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "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 :doc:`review register ` for the checks and decisions.