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## Full-Text Articles in Physics

Angular And Radial Correlation In Doubly Excited Systems When 1 ≤ Z ≤ 4. The 2p2 3p State, D. R. T. Keeble, K. E. Banyard, Gordon W. F. Drake

#### Angular And Radial Correlation In Doubly Excited Systems When 1 ≤ Z ≤ 4. The 2p2 3p State, D. R. T. Keeble, K. E. Banyard, Gordon W. F. Drake

*Physics Publications*

The angular and radial components of electron correlation have each been examined in detail for the discrete 2p2 3P states of H-, He, Li+ and Be2+. These doubly excited systems were described by highly accurate explicitly correlated wavefunctions. The analysis involved the use of angular Coulomb holes, changes in the one- and two-particle radial density distributions and several angular and radial expectation values. Additionally, various statistical correlation coefficients were used which emphasized, in turn, angular and radial correlation properties in different regions of the two-particle density. The angular holes and related properties showed a clearly defined inverse-Z effect for He ...

1/N Expansions For Two-Electron Coulomb Matrix Elements, Gordon W. F. Drake, R. N. Hills

#### 1/N Expansions For Two-Electron Coulomb Matrix Elements, Gordon W. F. Drake, R. N. Hills

*Physics Publications*

The study of 1/n expansions for various atomic matrix elements, where n is the principal quantum number, plays an important role in the theoretical foundations of the quantum defect method. The paper develops an expansion in powers of 1/n 2 for hydrogenic boundstate wavefunctions which can be used to calculate 1/n expansions of matrix elements. The 1/n expansions of the two-electron direct and exchange Coulomb integrals are evaluated as an example. © 1993 IOP Publishing Ltd.

Energy Corrections Of Order Mc2Α6lnα In Helium, Gordon W. F. Drake, I. B. Khriplovich, A. I. Milstein, A. S. Yelkhovsky

#### Energy Corrections Of Order Mc2Α6lnα In Helium, Gordon W. F. Drake, I. B. Khriplovich, A. I. Milstein, A. S. Yelkhovsky

*Physics Publications*

Quantum-electrodynamic corrections of O(mc2α6lnα) to the electron-electron interaction in helium are evaluated for several states. The additional energy shift, which is an order of α smaller than the leading Araki-Sucher terms, raises the predicted energy of the 1s2s 1S0 state by 2.49 MHz to -960 332 039.43(18) MHz relative to He+(1s). The new value significantly alters the comparison with recent high-precision experiments. © 1993 The American Physical Society.

Erratum: Energy Corrections Of Order Mc2Α6 In Α In Helium (Physical Review A (1993) 48, 6 (4804), Gordon W. F. Drake, I. B. Khriplovich, A. I. Milstein, A. S. Yelkhovsky

#### Erratum: Energy Corrections Of Order Mc2Α6 In Α In Helium (Physical Review A (1993) 48, 6 (4804), Gordon W. F. Drake, I. B. Khriplovich, A. I. Milstein, A. S. Yelkhovsky

*Physics Publications*

No abstract provided.

Erratum: Variational Calculation For The Ground State Of Lithium And Qed Corrections For Li-Like Ions (Physical Review A (1993) 48, 6 (4803)), D. K. Mckenzie, Gordon W. F. Drake

#### Erratum: Variational Calculation For The Ground State Of Lithium And Qed Corrections For Li-Like Ions (Physical Review A (1993) 48, 6 (4803)), D. K. Mckenzie, Gordon W. F. Drake

*Physics Publications*

No abstract provided.