References and Notes for Carbon ( C )
CBS86 A. L. Cooksy, G. A. Blake, and R. J. Saykally, Astrophys. J. 305, L89 (1986). These authors give high-accuracy values for the C II 2p 2P°3/2-2P°1/2 splitting for isotopes 12C and 13C, the value for 12C being 1900536.9(1.3) MHz (63.39509(5) cm-1).
CG98 E. S. Chang and M. Geller, Phys. Scr. 58, 326 (1998). Some of the separations of C I levels in this reference have estimated uncertainties less than 0.01 cm-1. The values here are rounded to two decimal places because the absolute uncertainty (with respect to the ground level) of even the best-determined levels higher than the 2s2p3 5S°2 level is about 0.04 cm-1 [J66, KW66, KE74].
CSBE86 A. L. Cooksy, R. J. Saykally, J. M. Brown, and K. M. Evenson, Astrophys. J. 309, 828 (1986).
J66 L. Johansson, Ark. Fys. 31, 201 (1966). Johansson's values for most of the best-known C I excited-configuration levels (with respect to the 2p2 3P0 ground level) agree with newer redetermined values [KW66, CG98] within 0.01 cm-1. The value of 90883.84(10) cm-1 for the C II 2p 2P°3/2 limit, as derived by Johansson from the C I 2pnp 3D3 series, is not changed significantly by the more recent work. His resulting value for the C II 2P°1/2 limit has been adjusted to the more accurate value of 63.395 cm-1 for the C II 2p 2P°3/2-2P°1/2 splitting [CBS86]. Given the absolute uncertainty of about 0.04 cm-1 for the 2pnp 3D levels and the additional uncertainty of the limit determination, Johansson's estimated uncertainty of 0.10 cm-1 for the ionization energy is reasonable. We used Johansson's wavenumbers for the two pertinent lines near 2965 Å together with the new 2p2 3P1 and 3P2 level values to adjust his 2s2p3 5S°2 level upwards by 0.02 cm-1.
JL65 L. Johansson and U. Litzén, Ark. Fys. 29, 175 (1965).
KE74 V. Kaufman and B. Edlén, J. Phys. Chem. Ref. Data 3, 825 (1974).
KW66 V. Kaufman and J. F. Ward, J. Opt. Soc. Am. 56, 1591 (1966).
M03 D. C. Morton, Astrophys. J. Suppl. Ser. 149, 205 (2003).
MG93 C. E. Moore, Tables of Spectra of Hydrogen, Carbon, Nitrogen, and Oxygen, J. W. Gallagher, ed., CRC Press, Inc., Boca Raton, FL (1993). The C II 2p 2P°3/2-2P1/2 separation of 63.42 cm-1 from this reference is 0.025 cm-1 larger than a more recent high-accuracy value [CBS86]. We have retained the older value for consistency with the other C II levels tabulated here, which have not been re-evaluated.
WFD96 W. L. Wiese, J. R. Fuhr, and T. M. Deters, J. Phys. Chem. Ref. Data, Monogr. 7 (1996).
YS91 S. Yamamoto and S. Saito, Astrophys. J. 370, L103 (1991).