Kopfermann (Ref. 15) gives expressions for sp and pp' magnetic dipole matrix elements and sp electric quadrupole matrix elements. The latter formula, first given by Casimir IH. Casimir, Teylors Tweede Genootshap 11, 255 (1936)] is inconsistent with the matrix elements in Ref. 16, and appears to be in error. The "12" in the third term on the right-hand side of Ref. 15, Eq. (31.4), should be a "6. " We wish to thank W. J. Childs for his helpful comments and for pointing this out. The isotopic mixture of the Ne sample used was 87. 9% Ne; 10.2% Ne2; 1.9% Ne R. M. Sternheimer, Phys. Rev. 84, 244 (1951). R. M. Sternheimer, Phys. Rev. 164, 10 {1967). R. M. Sternheimer and R. F. Peierls, Phys. Rev. A 4, 1722 (1971). R,. M. Sternheimer (private communication). We are grateful to Dr. Sternheimer for providing us with the results of his calculation. H. F. Schaefer, III and R. A. Klemm, Phys. Rev. A 1, 1063 (1970). Calculations of the LS admixture coefficients based on the fs energy splittings, including only spin-orbit and electrostatic interactions, are in excellent (0.1/~) agreement with the values quoted in Ref. 14 [Eq. (4)] for the 1s4 and 2s2 levels. For the 2P4 level, there is a difference of -5% in the coefficient of the dominant i P2) basis state.Calculated Auger, Coster-Kronig, super Coster-Kronig, and radiative transition rates are used to compute atomic M-shell Auger, Coster-Kronig, and fluorescence yields. Comparison is made with five fluorescence-field measurements, with full width athalf-maximum measurements of L-M x rays, and with Bhalla's relativistic radiative-yield calculations.

Calculated Auger, Coster-Kronig, and radiative transition rates are used to compute atomic L-shell Coster-Kronig and fluorescence yields. The results are compared with other calculations, experimental yield determinations, and radiative half-width measurements.

Using the generalized oscillator-strength formulation of the Born approximation, electron ionization cross sections were calculated for 20 elements with i9 & Z & 54. For Kr and Xe, good agreement (30%) is found for the total ionization cross section above 300 eV. Comparison with measured cross sections for producing various charge states in Kr and Xe showed significant discrepancies, which arise from neglect of configuration interaction. Comparison with measured total cross sections for other elements show limited agreement, though the agreement improves as one goes to higher Z.

The quantity -rV{r) for ions, formed by removing a Is electron from the neutral atom, is computed by the approach of Herman and Skillman. A straight-line approximation of -rV{r) is made, leading to an exactly solvable one-electron Schrodinger equation. The discrete and continuum orbitals are used to compute Auger KLL and KLM transition rates, radiative rates, and fluorescence yields for the elements Be-Ar. Comparison with experimental iC-shell fluorescence yields indicates the calculations are 25% too high for Mg and Al and within 5% for Ar. Comparison of the individual Auger transition intensities for F, Ne, Na, and Mg indicates differences of 50%. This 50% difference between calculated and measured individual Auger transition intensities persists up to Ar, where the sum of the individual intensities is in better than 7% agreement with that derived from the fluorescence yield and if-state width.

The excellent agreement between recent converged close-coupling calculations of electron ionization cross sections of atoms and ions and plane-wave Born approximation (PWBA) calculations leads to the hypothesis that PWBA calculations are accurate to 10% at high energy, and therefore can be used to renormalize experimental data to produce cross sections of 10% accuracy near threshold. Comparisons are made of various calculations of 2s and 3s electron ionization cross sections in low-Z atoms and ions, of PWBA calculations and experiments for atoms and ions up to Ba 1+ , and of scaled peak cross sections to interrelate experiments and calculations on isoelectronic sequences.