151 citations · 1.2k across the 19 of their papers we have counts for
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Helium energy levels including corrections
Krzysztof Pachucki
The correction to energy is expressed in terms of an effective Hamiltonian for an arbitrary state of helium. Numerical calculations are performed for levels…
Ry corrections to singlet states of helium
Krzysztof Pachucki
Corrections of order Ry are calculated for the singlet states and of the helium atom. The result for state is in slight disagreement with that of Ko…
Nonrelativistic QED approach to the Lamb shift
Ulrich D. Jentschura, Andrzej Czarnecki, Krzysztof Pachucki
We calculate the one- and two-loop corrections of order alpha(Zalpha)^6 and alpha^2(Zalpha)^6 respectively, to the Lamb shift in hydrogen-like systems using the formalism of nonrel…
Calculation of the One- and Two-Loop Lamb Shift for Arbitrary Excited Hydrogenic States
Andrzej Czarnecki, Ulrich D. Jentschura, Krzysztof Pachucki
General expressions for quantum electrodynamic corrections to the one-loop self-energy [of order alpha(Zalpha)^6] and for the two-loop Lamb shift [of order alpha^2(Zα)^] are derive…
Improved theory of helium fine structure
Krzysztof Pachucki
Improved theoretical predictions for the fine-structure splitting of levels in helium are obtained by the calculation of contributions of order . New results for t…
Ground state wave function and energy of the lithium atom
Mariusz Puchalski, Krzysztof Pachucki
Highly accurate nonrelativistic ground-state wave function and energy of the lithium atom is obtained in the Hylleraas basis set. The leading relativistic corrections,as represente…