Energy Positions of the ^1,3D^eRydberg Series of the He-Like Ions Up to the <i>N</i>= 9 Threshold

The doubly excited states of helium-like ions are investigated using a combination of the no-linear parameters of Hylleraas and the β-parameters of screening constant by unit nuclear charge. Calculations are performed for total energies of low-lying doubly excited states (N = 2 - 9) in He-like ions up to Z = 10. The results obtained from the novel method are in good agreement with the available theoretical calculations and experimental observations.

Modified Atomic Orbital Theory of the O+ Ion Originating from 2D0 and 4S0 Metastable States

We report in this paper energy positions of the 2D0_2s22p2(1D)nd(2F);2D0_2s22p2(1D)nd(2D);2D0_2s22p2(1D)nd(2P);2D0_2s22p2(1D)ns(2D);2D0_2s22p3(3D)np(2P);2D0_2s22p3(3D0)np(2F), and 4S0_2s22p3(5S0)np(4P) Rydberg series in the photoionization spectra originating from 2D0 and 4S0 metastable states of O+ ion. Calculations are performed up to n = 20 using the Modified Orbital Atomic Theory (MAOT) [1]. The present results are compared to the experimental data of Aguilar et al. [2] which are the only available values. The accurate data presented in this work may be a useful guideline for future experimental and other theoretical studies.

Variational Calculations of Energies of the (2<i>snl</i>) ^1,3<i>L^π</i>and (2<i>pnl</i>) ^1,3<i>L^π</i>Doubly Excited States in Two-Electron Systems Applying the Screening Constant per Unit Nuclear Charge

In this paper, resonance energies and excitation energies of doubly 2sns 1,3Se, 2snp 1,3P0, 2pnp 1,3De, 2pnd 1,3F0 and 2pnf 1,3Ge excited states of the helium isoelectronic sequence with Z ≤ 10 are calculated. Calculations are carried out in the framework of the variational procedure of the formalism of the Screening Constant per Unit Nuclear Charge (SCUNC). New correlated wave function of Hylleraas type is used. Precise resonance and excitation energies are tabulated and good agreement is obtained when a comparison is made with available literature values.

Modified Atomic Orbital Calculations of Energy of the(2s^(2)^(1)S)Ground-State,the(2p^(2)^(1)D);(3d^(2)^(1)G)and(4f^(2)^(1)I)Doubly Excited States of Helium Isoelectronic Sequence from H-to Ca^(18+)

We report in this paper the ground-state energy 2s^(2)^(1)S and total energies of doubly excited states 2p^(2)^(1)D,3d^(2)^(1)D,4f^(2)^(1)I of the Helium isoelectronic sequence from H-to Ca^(18+).Calculations are performed using the Modified Atomic Orbital Theory(MAOT)in the framework of a variational procedure.The purpose of this study required a mathematical development of the Hamiltonian applied to Slater-type wave function[1]combining with Hylleraas-type wave function[2].The study leads to analytical expressions which are carried out under special MAXIMA computational program.This first proposed MAOT variational procedure,leads to accurate results in good agreement as well as with available other theoretical results than experimental data.In the present work,a new correlated wave function is presented to express analytically the total energies for the 2s21S ground state and each doubly 2p^(2)^(1)D,3d^(2)^(1)D,4f^(2)^(1)I excited states in the He-like systems.The present accurate data may be a useful guideline for future experimental and theoretical studies in the(nI^(2))systems.

Photoionization Study of the 2s^(2)2p^(2)(^(1)D)ns(^(2)D),2s^(2)2p^(2)(^(1)D)nd(^(2)P),2s^(2)2p^(2)(^(1)D)nd(^(2)S),2s^(2)2p^(2)(^(1)S)nd^(2)D,and 2s^(2)2p^(3)(^(3)P)np(^(2)D)Rydberg Series of O+Ions via the Modified Atomic Orbital Theory

We report in this paper energy positions of the 2P˚_2s^(2)2p^(2)(^(1)D)nd 2P,2P˚_2s^(2)2p^(2)(^(1)D)nd 2S,2P˚_2s^(2)2p^(2)(^(1)D)ns^(2)D,2P˚_2s^(2)2p^(2)(^(1)S)nd ^(2)D,and 2P˚_2s^(2)2p^(3)(^(3)P)np ^(2)D Rydberg series in the photoionization spectra originating from 2P˚metastable state of O+ions.Calculations are performed up to n=30 using the Modified Orbital Atomic Theory(MAOT).The present results are compared to the experimental data of Aguilar which are the only available values.The accurate data presented in this work may be a useful guideline for future experimental and other theoretical studies.

Photoionization Study of Cl II, Ar II and Kr II Ions Using the Modified Atomic Orbital Theory

Resonance energies of the Cl II-[3s23p3(2D5/2)]nd and [3s23p3(2P3/2)]nd, Ar II-3s23p4(1D2)ns, nd and of the Kr II [4s24p4(1D2)]ns, nd and 4s24p4(3P2,3P1)]ns, 4s24p4(3D2)]ns, nd and 4s24p4(3D2, 1S0)]ns, nd Rydberg series are reported. Natural widths of the Ar II-[3s23p4(1D2)]ns, nd series are also reported. Calculations are done in the framework of the Modified Atomic Orbital Theory (MAOT). Excellent agreements are obtained with available theoretical and experimental data. High lying accurate resonance energies up to n = 40 are tabulated. The possibility to use the MAOT formalism report rapidly with an excellent accuracy the position of the excitation resonances as well as their width within simple analytical formulae is demonstrated.

Calculations Energy of the (<i>nl</i>²) ¹<i>L^π</i>Doubly Excited States of Two-Electron Systems via the Screening Constant by Unit Nuclear Charge Formalism

In this work, the total energies of doubly excited states (ns2) 1Se, (np2) 1De, (nd2) 1Ge, (nf2) 1Ie, (ng2) 1Ke, and (nh2) 1Me of the helium isoelectronic sequence with Z ≤ 10 are calculated in the framework of the variational method of the Screening Constant by Unit Nuclear Charge (SCUNC). These calculations are performed using a new wavefunction correlated to Hylleraas-type. The possibility of using the SCUNC method in the investigation of high-lying Doubly Excited States(DES) in two-electron systems is demonstrated in the present work in the case of the (nl2) 1Lπ doubly excited states, where accurate total energies are tabulated up to n = 20. All the results obtained in this paper are in agreement with the values of the available literature and may be useful for future experimental and theoretical studies on the doubly excited (nl2) 1Lπ states of two-electron systems.