helike_jl1989o.dat

• Spontaneous Emission: O⁺⁶(i) → O⁺⁶(j) + hv
• Electron Impact Excitation: O⁺⁶(i) + e → O⁺⁶(j) + e

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  Energy levels
  Taken from NSRDS NBS 3 Sect 8

  Ionisation  Potential
  Taken from Kelly (J Phys Chem Ref Data 16, 1987)

  A values
  These were taken from Kingston and Tayal (J Phys B 16, 3465, 1985). This
  was an eleven state CIV3 (Hibbert) calculation. There was good agreement
  between the length and velocity formulations, the results only differing
  by more than 4% for 2 transitions. One of these had a small f value and
  the other was the 1 1S - 3 1P transition for which the difference was 12%.
  There was good agreement with the results of Schiff et al (Phys Rev A4,
  885, 1971) and Weiss (1964 as quoted in Weise, Smith and Glennon NSRDS
  NBS4 1966), the largest difference being 10% for the  1 1S - 3 1P
  transition.

  Collision Data
  For transitions from 1 - 2 to 1 - 11 inclusively, the results of Tayal and
  Kingston (J Phys B 17, 1383, 1984) were used. These were based on their
  earlier work (J Phys B 16, 3465, 1983 and J Phys B 16, L53, 1983). This
  was an eleven state close coupling R matrix calculation with th R matrix
  boundary at 6.5 au. The largest energy considered was 120 Rydbergs. At each
  electron energy results were obtained for 6 values of angular momentum L =0
  to 5. This gave convergence for spin changing transitions. For transitions
  without spin change, they calculated partial cross sections for L=6 to 20
  using the Coulomb Born approximation with the same target wavefunctions as
  in the R matrix calculation ( ie also as in the A value calculation).
  This gave converged cross sections.

  For 2 - 3, 4 and 5 and 3 - 4 and 5 and 4 - 5 transitions the results of
  Pradhan, Norcross and Hummer (Astrophysics J 246, 1031, 1981) were used.
  This was a Distorted Wave (5DW + 3ll') claculation with configuration
  interaction wavefunctions. The total wavefunction included expansion over
  the target staes of the ion as well as a second one over functions
  representing bound states of the electron plus ion system. The second sum
  was included for orthogonality and because it represented short range
  correlation effects. The correlation functions also represent autoionising
  resonance states. They were used to take account of resonances above
  all the n = 2 thresholds. MQDT was used in addition to get the structure of
  the resonances. Restricted to resonances converging on n = 3 states.

  For n = 6 to n = 11 for n from 2 to 5, the results of Sampson, Goett and
  Clark (Atomic Data and Nuclear Data Tables 29, 467, 1983) were used. They
  used the Coulomb Born Exchange method and included intermediate coupling
  effects but not the effects of resonances.

  For transitions from levels 6, 7, 8, 9 and 10 to higher levels the results
  of Sampson and Parks (Astrophysics J Supp. Series 28, 323, 1974) were used.
  They gave a general formula for ions of large Z with one or two electrons
  when the core of filled subshells remains unexcited. Thought to be accurate
  to within 40% for Z/N >= 3 where N is the number of bound electrons per
  ion.


  J Lang    February 1990

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Contributors

• Jim Lang
• K P Dere
• Douglas Sampson