34 citations · 136 across the 11 of their papers we have counts for
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Entanglement entropies in the ground states of helium-like atoms
Przemyslaw Koscik, Anna Okopinska
We examine the entanglement in the ground states of helium and helium-like ions using an original Hylleraas expansion. The von Neumann and linear entropies of the reduced density m…
Coupled anharmonic oscillators: the Rayleigh-Ritz approach versus the collocation approach
Arkadiusz Kuros, Anna Okopinska
For a system of coupled anharmonic oscillators we compare the convergence rate of the variational collocation approach presented recently by Amore and Fernandez (2010 Phys.Scr.81 0…
The optimized Rayleigh-Ritz scheme for determining the quantum-mechanical spectrum
Przemyslaw Koscik, Anna Okopinska
The convergence of the Rayleigh-Ritz method with nonlinear parameters optimized through minimization of the trace of the truncated matrix is demonstrated by a comparison with analy…
Two-electron entanglement in elliptically deformed quantum dots
Przemyslaw Koscik, Anna Okopinska
Entropic entanglement measures of a two-dimensional system of two Coulombically interacting particles confined in an anisotropic harmonic potential are discussed in dependence on t…
Quasi-exact solutions for two interacting electrons in two-dimensional anisotropic dots
Przemyslaw Koscik, Anna Okopinska
We present an analysis of the two-dimensional Schrodinger equation for two electrons interacting via Coulombic force and confined in an anizotropic harmonic potential. The separabl…
Application of the Frobenius method to the Schrodinger equation for a spherically symmetric potential: anharmonic oscillator
Przemyslaw Koscik, Anna Okopinska
The power series method has been adapted to compute the spectrum of the Schrodinger equation for central potential of the form $V(r)={d_{-2}\over r^2}+{d_{-1}\over r}+\sum_{i=0}^{\…