Larissa V. Chernysheva

Larissa V. Chernysheva
Ioffe Institute | ioffe · Sector of Solid State Theory

Dr. Sc.

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218
Publications
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2,094
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52 Research Items
470 Citations
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2017201820192020202120222023020406080100
2017201820192020202120222023020406080100
2017201820192020202120222023020406080100
Introduction
Прошу исправить мое отчество: Чернышева Лариса Владимировна
Skills and Expertise
Additional affiliations
October 1992 - present
Ioffe Physical Technical Institute, St. Petersburg
Position
  • Leading scientist
September 1992 - October 2015
Russian Academy of Sciences
Position
  • Leading Researcher
September 1992 - October 2015
Ioffe Institute
Position
  • Leading Researcher

Publications

Publications (218)
Article
Full-text available
Satellites i.e. two-hole-one-particle states appear due to many-electron correlations in photoelectron spectra in addition to main lines corresponding to one-hole states. The correct assignment of these states is important for understanding the photoionization processes and for materials analysis by photoelectron spectroscopy. In the present work t...
Article
Full-text available
The article is devoted to a brief description of the ATOM computer program system, designed to study the structure, transition probabilities and cross sections of various processes in multielectron atoms. The theoretical study was based on the concept of a computational experiment, the main provisions of which are discussed in the article. The main...
Chapter
This chapter describes a method for calculating the bremsstrahlung of incident high and intermediate energy electrons scattered by an atom, taking into account the dynamic polarization of the target atom by the incident particle in the collision process. Formulas are given for calculating the form factor, bremsstrahlungBremsstrahlung cross section,...
Chapter
This chapter describes the structure of ATOM-M system software. This system is organized as a set of modules of various types. Executive modulesExecutive modules are computational programs that solve certain physical problems using procedures (modules) of other types. Executive modules that solve new, similar to those discussed, physical problems c...
Chapter
In this chapter, we discuss the angular distributions of photoelectrons and secondary electrons knocked out from the target in the process of inelastic scattering of fast electrons. Their general and specific features are investigated, demonstrating a significant difference in the corresponding characteristics of the two processes under considerati...
Chapter
This chapter describes the procedures for calculating the spin polarization parameters in the dipole approximationDipole approximation and with account of the lowest non-dipole corrections. The results of these calculations are presented in [AICC].
Chapter
This chapter describes the main programs of the ATOM-M system. Each program corresponds to an independent physical problem related to the study of the structure of atoms and the calculation of the probabilities of atomic processes. The choice of approach is described for each investigated problem.
Chapter
In this chapter, we consider the cross section for scattering of fast electrons by endohedrals [1, 2]. This cross section is expressed in terms of generalized oscillator strength (GOS). Formulas are given for calculating the angular distributions of secondary electrons emitted from the endohedral during its ionization. The general approach is simil...
Article
Full-text available
We theoretically study the positron elastic scattering by an atom with a multielectron semifilled subshell in its structure. We focus on gaining the initial insight into the specifics of such a process. The positron scattering by the Mn(…3d ⁵ 4s ² , ⁶ S) atom with a 3d ⁵ semifilled subshell (e ⁺ + Mn scattering) is chosen as a case study. We accoun...
Preprint
We theoretically study the positron elastic scattering by an atom with a multielectron semifilled subshell in its structure. The positron scattering by the Mn($...3d^{5}4s^{2}$,$^{6}S)$ atom with a $3d^{5}$ semifilled subshell ($e^{+}+Mn$ scattering) is chosen as a case study. We account for both the electron correlation and the formation of a $e^{...
Chapter
This chapter shows how, using the wave functions of the ground and excited single-electron states, as well as the wave functions of an incident and inelastically scattered electron, one can calculate the cross section for ionization and excitation of an atom by electron impact in the Born approximation with plane and distorted waves. In the latter...
Chapter
Consideration in the Hartree–Fock–Dirac approximation of any process in which an atom participates requires knowledge of the wave functions of the excited states. This chapter proposes the simplest approach to calculating one-particle wave functions in discrete and continuous spectra. In this case, as a rule, the frozen core approximation is used,...
Chapter
This chapter proposes a method for numerical solution of nonrelativistic Hartree–Fock equations for atoms, simple molecules, and endohedrals. The need to solve these equations is determined by the fact that many of the processes under consideration are nonrelativistic, while the solution of relativistic equations for many calculations related to in...
Chapter
This chapter outlines a general approach to the method developed in this book for constructing mathematical models for describing physical processes in atoms and simple molecules.
Chapter
This chapter contains the basic formulas that are used in calculating the characteristics of the process of atoms and simple molecules interaction with electromagnetic radiation. The necessary details of the calculation technique are given for objects with closed and open subshells and levels, as well as with semi-closed subshells.
Chapter
Generalized oscillator strengths (GOS) are characteristics that describe the process of interaction of a fast, charged particle with an atom or molecule. This chapter describes how to calculate GOS for electrons in the one-particle Hartree–Fock and RPAE approximations that account for the interaction of various transitions. RPAE equations are prese...
Chapter
This chapter describes the one-photon decay of single- and double-hole states of atoms. One-photon decay is a process in which the initial state—one or two vacancies—decays with emission of a single photon. Formulas are given for calculating the amplitudes and probabilities of these processes.
Chapter
This chapter contains all the information you need to read and understand this book. The main physical features of the structure of atoms, simple molecules, fullerenes, and endohedrals are discussed, definitions of concepts that are used throughout the book are given, and a diagrammatic description of all the processes under consideration is presen...
Chapter
This chapter provides formulas for calculating the Auger widths of atomic levels, both in the one-electron approximation and with the inclusion of corrections in this process in the framework of RPAE and perturbation theory. A method is presented to calculate the probability of double Auger decay, i.e., a process in which two vacancies decay with t...
Book
This book presents numerical methods for solving a wide range of problems associated with the structure of atoms and simplest molecules, and their interaction with electromagnetic radiation, electrons, and other particles. It introduces the ATOM-M software package, presenting a unified software suite, written in Fortran, for carrying out precise at...
Chapter
This chapter discusses endohedrals photoionization cross section and corresponding dipole and non-dipole angular distributions of photoelectrons. Fullerene, inside which atom A is located, is considered approximately as a static potential of zero or finite thickness. In addition, dipole and quadrupole fullerene polarization under the action of inco...
Chapter
This chapter describes a method for calculating the cross section of a process in which a photoelectron on its way from an atom collides inelastically with the residual ion, thus changing its own energy, angular momentum, and spin projection. Formulas are given for calculating the photoabsorption dipole matrix elements and the photoionization cross...
Chapter
Each specific physical problem requires the choice of the initial basis of wave functions for its consideration. Obtaining the characteristics of a physical processPhysical process requires knowledge of the wave functions in the ground and excited states.
Chapter
In this chapter, we present an approach to calculating the GOS density differential in the angle of the outgoing electron and the angular anisotropy parameters for secondary electrons in the scattering of fast particles for intermediate values of the momentum q transferred from the projectile to the target atom. For small values of q, the same para...
Chapter
This chapter provides examples of results obtained using the ATOM-M system. Examples of both intermediate and final calculation results are given—wave functions and matrix elements, as well as cross sections of processes and excitation probabilities for absorbing photons, scattering of electrons, positrons, and muons. Atoms, endohedrals, and diatom...
Chapter
Consideration of any process involving an atom or a simple molecule requires knowledge of the wave functions of the excited states. This chapter proposes the simplest approach to calculating one-particle wave functions in discrete and continuous spectra. In this case, as a rule, the so-called frozen core approximation is used, in which it is assume...
Chapter
In this chapter, a connection is established between the self-energy part of the single-particle Green’s function and the phase shift of the incident particle in elastic scattering, as well as the shift in the energy of the atomic electron caused by correlation effects. Formulas for calculating the phase shifts of inelastic scattering are presented...
Chapter
This chapter discusses a method for solving simplified Hartree–Fock–Dirac (HFD) equations, which are obtained from exact HFD equations by dropping parametrically small terms. We take into account that even in heavy atoms electrons of only the inner and partly intermediate shells are relativistic.
Article
In this Letter, we investigate the non-dipole effects in time delay of photoelectrons emitted by multi-electron atoms, negative ions, and respective endohedrals. We present the necessary general formulas in the frame of the random phase approximation with exchange (RPAE) applied to atoms, negative ions, and properly adjusted to endohedrals. We conc...
Preprint
In this Letter, we investigate the non-dipole effects in time delay of photoelectrons emitted by multi-electron atoms, negative ions, and respective endohedrals. We present the necessary general formulas in the frame of the random phase approximation with exchange (RPAE) applied to atoms, negative ions, and properly adjusted to endohedrals. We conc...
Article
In this Letter, we investigate the time delay of photoelectrons by fullerenes shell in endohedrals. We present general formulas in the frame of the random phase approximation with exchange (RPAE) applied to endohedrals A@CN that consist of an atom A located inside of a fullerenes shell constructed of N carbon atoms C. We calculate the time delay of...
Chapter
We study properties of atoms, in which substitute fermions–electrons by bosons, namely \( \pi^{ - } \)-mesons. We perform calculations in the frame of modified Hartree-Fock (HF) equation. The modification takes into account symmetry of the pair of identical bosons wave function, doubling instead of eliminating self-action as in the Fermion case. As...
Article
Full-text available
We investigate here the variation of endohedral A@CN potential due to instant ionization of an inner atom A. Using a reasonable model to describe the fullerenes shell, we managed to calculate this variation that is a consequence of the monopole polarization of CN shell. We demonstrate that the phenomenological potentials that properly simulate the...
Article
Full-text available
Synopsis We developed a semi-phenomenological approach that permits to calculate the photoionization cross section of an endohedral A@C N . We take, along with the static pseudopotential of atom A and fullerene C N also the static and dynamic polarization of A and C N by the incoming photons and outgoing electrons. The approach is general and appli...
Article
Full-text available
Synopsis We study theoretically the experimental angle-differential elastic electron scattering off a C 60 fullerene with the aim to elucidate whether its features depend primarily on the details of the full molecular potential of C 60 or they can be understood without reference to the full nature of the potential. We demonstrate the success of the...
Article
We have calculated partial contributions of different endohedral and atomic subshells to the total dipole sum rule in the frame of the random phase approximation with exchange (RPAE) and found that they are essentially different from the numbers of electrons in respective subshells. This difference manifests the strength of the intershell interacti...
Preprint
Full-text available
In this Letter, we investigate the variation of endohedral A@CN potential due to addition at the center of it a positive charge, for example, in the process of atom A photoionization. Using a reasonable model to describe the fullerenes shell, we managed to calculate the variation that is a consequence of the monopole polarization of CN shell. We an...
Article
We calculate the photoionization cross-section of a molecular endohedral that denote as M@CN. We limit ourselves to two-atomic molecules. The consideration is much more complex than for atomic endohedrals because the system even for almost spherical CN has only cylindrical instead of spherical symmetry. On the other hand, M@CN is more interesting s...
Preprint
We have calculated partial contributions of different endohedral and atomic subshells to the total dipole sum rule in the frame of the random phase approximation with exchange (RPAE) and found that they are essentially different from the numbers of electrons in respective subshells. This difference manifests the strength of the intershell interacti...
Preprint
We calculate the photoionization cross-section of a molecular endohedral. We limit ourselves to two-atomic molecules. The consideration is much more complex than for atomic endohedrals because the system even for almost spherical fullerenes has only cylindrical instead of spherical symmetry. On the other hand, molecular endohedral is more interesti...
Article
Full-text available
We prove in the present paper that simple modeling of a complicated highly polarizable C 60 target by a rectangular (in a radial coordinate) square well potential in combination with the static polarization potential provides a viable approximation for a low-energy elastic-electron scattering off this target. The proof is based on the results of th...
Article
We have calculated photoionization cross-section of endohedral atoms A@CN. We took into account the polarizability of the fullerene electron shell CN that modifies the incoming photon beam and the one-electron wave functions of the caged atom A. We employ simplified versions of both static and dynamic polarization. The properly modified one-electro...
Preprint
We have calculated photoionization cross-section of endohedral atoms A@CN. We took into account the polarizability of the fullerene electron shell CN that modifies the incoming photon beam and the one-electron wave functions of the caged atom A. We employ simplified versions of both static and dynamic polarization. The properly modified one-electro...
Preprint
We prove in the present paper that a simple modeling of a complicated highly polarizable C$_{60}$ target by a rectangular (in a radial coordinate) square well potential in combination with the static polarization potential provides a viable approximation for a low-energy elastic electron scattering off this target. The proof is based on the results...
Article
We have calculated partial contributions of different atomic subshells to the total dipole sum rule in the frame of the random phase approximation with exchange and found that they are essentially different from the numbers of electrons in respective subshells. This difference manifests the strength of the intershell interaction, due to which some...
Preprint
We demonstrate that in the frame of the random phase approximation with the exchange, which preserves the validity of the precise well known dipole sum rule, the partial contributions for given subshells strongly deviates from the number of electrons in these subshells. This demonstrates strong effects of intershell interaction in atoms.
Poster
The study of elastic positron scattering off half-filled shell atoms (with the Mn atom as the case study) with and without account for electron correlation, with and without account for the positronium (e-e+) formation in the process of scattering, and the study of how elastic positron scattering differs from the corresponding electron scattering.
Conference Paper
Positron-atom (e^{+} + A) scattering is an interesting and important process the study of which has a long history. Compared to electron scattering (e^{−} + A), e^{ +} + A scattering is a much more subtle elementary process owing to the possibility of the formation of a virtual positronium during the scattering process [1]. Many methods have been d...
Article
We investigate here ground state properties of atoms, in which substitute fermions -- electrons by bosons, e.g. $\pi $ - meson. We perform some calculations in the frame of modified Hartree-Fock (HF) equation. The modification takes into account the symmetry, instead of anti-symmetry of the two-identical bosons wave function. The modified HF approa...
Article
Full-text available
Ramsauer-type minima in e ⁻ + C60 partial electron elastic scattering cross sections, brought about by C60 polarization, and their exposition to light in the angle-differential scattering cross section are revealed and detailed.
Article
We investigate positron scattering upon endohedrals and compare it with electron-endohedral scattering. We show that the polarization of the fullerene shell considerably alters the polarization potential of an atom, stuffed inside a fullerene. This essentially affects both the positron and electron elastic scattering phases as well as corresponding...
Article
We have developed an efficient approximation to describe the low-energy electron elastic scattering off an endohedral fullerene A@C$_{N}. It accounts for polarization of A@C_{N} by incoming electrons without reference to complicated details of the electronic structure of C$_{N} itself. The developed approach has permitted us to unravel spectacular...
Article
Full-text available
The excitations of the electron shell in neutrinoless double beta decay shifts the limiting energy available for ejected electrons. We present the general equations for this shift and make computations for the decays of two nuclei—germanium and xenon.
Article
We demonstrate that the limiting energy available for ejected electrons in the double-β decay is diminished by about 400 eV due to inelastic processes in the atomic electronic shell.
Article
Full-text available
A deeper insight into electron elastic scattering off endohedral fullerenes A@C60 is provided. The study accounts for polarization of both the encapsulated atom A and C60 cage by an incident electron. It is carried out in the framework of the combination of both a model and the first-principle approximations. A core principle of the model is that t...
Poster
Full-text available
In the present work, we provide a deeper insight into e + A@C60 scattering by utilizing the approximation which accounts for polarization of both C60 and atom A by an incident electron. The emphasis is not only on the study of the polarization effects themselves, but on their sensitivity to the size and polarizability of the encapsulated atom A (A...
Poster
Full-text available
We provide the review of our successive model approximations to the e + A@C60 scattering problem along the path: “frozen A and frozen C60” [1,2] -> “polarizable atom, but frozen C60” [3] -> “simultaneously but independently (uncoupled) polarizable A and C60” -> “coupled polarizable A and polarizable C60”, and how these types of successive improveme...
Article
Full-text available
We demonstrate that the limiting energy available for ejected electrons in double beta decay is diminished by about 400 eV due to inelastic processes in the electronic shell.
Article
We demonstrate that the cross sections for photoionization of the outer shells are noticeably modified at the photon energies close to the thresholds of ionization of the inner shells due to correlations with the latter. The correlations may lead to increase or to decrease of the cross sections just above the ionization thresholds.
Conference Paper
Full-text available
A deeper insight into a complicated multi-faceted problem of low-energy electron elastic scattering off endohedral fullerenes, labelled A@C 60 , where A is an atom encapsulated inside the hollow interior of a C 60 fullerene, is unravelled. The " zeroth order " insight into the problem was provided earlier [1, 2] in the framework of a model static-e...
Article
Full-text available
We have demonstrated that the polarization of the fullerene shell considerably alters the polarization potential of an atom, stuffed inside a fullerene. This essentially affects the electron elastic scattering phases as well as corresponding cross-sections. We illustrate the general trend by concrete examples of electron scattering by endohedrals o...
Article
Full-text available
The present paper explores possible features of electron elastic scattering off endohedral fullerenes A@C60. It focuses on how dynamical polarization of the encapsulated atom A by an incident electron might alter scattering off A@C60 compared to the static-atom-A case, as well as how the C60 confinement modifies the impact of atomic polarization on...
Article
Full-text available
It is demonstrated that an inner atom, either Ne or Ar, qualitatively affects the electron scattering phases upon an endohedral, in spite of the fact that the fullerene consists of 60 carbon atoms, while the atom staffed inside is only one. Calculations are performed in the one-electron Hartree-Fock (HF) and random phase approximation with exchange...
Article
Full-text available
We have studied the role of virtual excitations of inner shells upon outer shell photoionization. The calculations were performed in the frames of the Random Phase Approximation with Exchange (RPAE) and its generalized version GRPAE that take into account variation of the atomic field due to electron elimination and the inner vacancies decay. We ap...
Article
Full-text available
We have studied the role of virtual excitations of inner shells upon outer shell photoionization. The calculations were performed in the frames of the Random Phase Approximation and its generalized version GRPAE that take into account variation of the atomic field due to electron elimination and the inner vacancies decay. We employ both analytic ap...
Conference Paper
Full-text available
A recent work [1] has provided the initial insight into electron elastic scattering off endohedral atoms A@C60. There, the atom A and C60 cage were regraded as non-polarizable targets. A question of how lifting the rigid-A-rigid-C60 constrain can affect e + A@C60 scattering has remained open. The present study provides a partial insight into the pr...
Article
Full-text available
We have studied the energy dependence of several first scattering phases with multi-atomic object. As concrete examples representing the general trends endohedrals Neon inside C60 and Argon inside C60 are considered. It appeared that the presence of an inner atom, either Ne or Ar, qualitatively affects the scattering phases, in spite of the fact th...
Article
Full-text available
Electron elastic scattering off a spin-polarized Cr(. . . 3d54s1, 7S) atom is theoretically studied in the region of electron energies up to 15 eV using both a one-electron “spin-polarized” Hartree-Fock approximation and a multielectron spin-polarized random-phase approximation with exchange. It is found that scattering phase shifts of oppositely s...
Article
Full-text available
Electron elastic scattering off a spin-polarized Cr(...$3d^{5}4s^{1}$, $^{7}S$) atom is theoretically studied in the region of electron energies up to $15$ eV using both a one-electron "spin-polarized" Hartree-Fock and multielectron "spin-polarized" random phase approximation with exchange. It is found that scattering phase shifts of oppositely spi...
Conference Paper
Full-text available
The Cr (...3d5 4s1, 7S) and Mn(...3d5 4s2 , 6 S) atoms belong to the cohort of high spin atoms, owing to their semifilled 3d5 and 4s1 (in Cr) subshells. The current understanding of low-energy electron scattering off such atoms is rudimentary. Here, we scrutinize the impacts of electron correlation, exchange, and electron spin-polarization on elast...
Article
We demonstrate that what is called a total photoionization cross section in the work by T. W. Gorczyca, M. F. Hasoglu, and S. T. Manson [Phys. Rev. A 86, 033204 (2012)] is in fact a partial photoionization cross section. These quantities differ impressively even in isolated atoms. This demonstrates the prominent role of inelastic collisions of a ph...
Article
Full-text available
We suggest an explanation of the recently observed discrepancy between the experimental and theoretical results on ionization of atoms, encapsulated into the fullerenes by photons with the energies of about 80-190eV. On the ground of previous theoretical considerations we conclude that the photoionization of the caged atom without excitation of the...
Article
Full-text available
We demonstrate serious misrepresentation of existing experimental data and important omissions in the List of references in the paper [1]. We demonstrate that what is called in [1] total photoionization cross-section is in fact a partial photoionization cross-section. We demonstrate that long before [1] and presented there experimental data for pho...
Conference Paper
Full-text available
Atoms with multielectron semifilled shells in their ground states possess the highest spin multiplicity among other atoms. The current understanding of electron scattering off such atoms is rudimentary. Choosing e+Mn(3d^{5}4s^{2}, ^{6}S) elastic scattering as a case study, we scrutinize scattering phase shifts, partial, and total scattering cross s...
Article
Full-text available
The impact of both exchange interaction and electron correlation, as well as their combined impact, on electron elastic scattering off a semifilled-shell Mn(. . . 3d54s2, 6S) atom are theoretically studied in the electron energy range of � = 0–25 eV. Corresponding elastic-scattering phase shifts δ�(�) as well as partial σ�(�) and total σ(�) cross s...
Article
Full-text available
It is demonstrated that the results of recent experiments on ionization of 3p and 3s electrons in Ni film and solid body [1] cannot be reproduced in the frames either Hartree-Fock or the random phase approximation with exchange. The difference between experimental data and calculation results is so big that from the theoretical side it requires inc...
Article
We calculate here the main characteristic of the fast electron scattering on endohedrals, namely their generalized oscillator strength (GOS), total and differential in the angle of atomic electron emission. Endohedrals are atoms A staffed inside the fullerene CN and denoted as A@CN. We take into account two major effects of CN on ionization of the...
Article
The response of endohedral Xe@C60 to fast electron impact ionization is theoretically studied by calculating its 4d, 5s and 5p generalized oscillators strengths (GOS). The calculation methodology combines the plane wave Born approximation, single-electron Hartree-Fock approximation, and multi-electron random phase approximation with exchange, all i...
Article
Fullerenes C60 can be stuffed by almost all atoms A or even simple molecules. It is demonstrated by the example of the 5p-subshell of the Xe atom stuffed inside the C60 fullerene, i.e. the endohedral Xe@C60 that the so-called confinement resonances in 4d subshell strongly affect the absolute and differential in the photoelectron emission angle cros...
Chapter
Full-text available
In this chapter, we provide figures and tables that represent data collected in the study of total and partial photoionization cross-sections, relative cross-sections, dipole and non-dipole parameters of angular anisotropy and spin polarization of photoelectrons, as well as the oscillator strengths of discrete excitations. In some cases, experiment...
Chapter
A vacancy created in any atomic shell, except of the outermost one, can decay or undergo a transition into other states with one or more vacancies.
Chapter
As photoabsorption or photoionization in this book we consider a process, in which a photon of energy ω and momentum κ, κ ;= ω ∕ c (c is the speed of light) is absorbed by a target—an atom or an ion. As a result, the target object can be either excited or ionized. Excitation means a transition of an atom or ion to one or several discrete energy lev...
Chapter
In this chapter, we collect and comment figures and tables, which present data, obtained in calculations of photoelectron satellite intensities and line shapes, intensities of Auger spectra, some line shapes of low-energy Auger lines, and radiation widths.
Chapter
This book contains the results of calculations of cross-sections and the probabilities of a wide range of atomic processes involving photons and electrons.
Chapter
Electron–atom scattering is a process that takes place at natural conditions and in laboratory. The data of this process are required in other domains of physics and technology. They also serve as source of information on atomic structure and properties and on efficiency of different theoretical approaches that are used to describe the process of e...
Chapter
In this chapter, we collect figures and tables that present the data obtained in the investigation of elastic and inelastic scattering cross-sections of slow, medium-energy, and fast electrons e and relatively slow positrons e. We will present total and partial, different in angle and energy, Compton scattering cross-sections for a number of atoms...
Chapter
In this chapter we present data for photoionization cross-sections beyond the energy conservation frame, or off-shell photoionization which are required for calculations of excited vacancy states. In Chaps. 5 and 6 we studied decay of not only simple HF vacancies but of more complex excited states that consist of several electrons and vacancies. Th...
Article
Full-text available
We present the angular distribution of electrons knocked out from an atom in a fast charge particle collision at small momentum transfer. Not only dipole, but also quadrupole transitions determine this distribution. The contribution of these transitions can be considerably enhanced as compared to the case of photoionization. In photoionization angu...
Book
The aim of this book is to present highly accurate and extensive theoretical Atomic data and to give a survey of selected calculational methods for atomic physics, used to obtain these data. The book presents the results of calculations of cross sections and probabilities of a broad variety of atomic processes with participation of photons and elec...
Article
Full-text available
The impact of both confinement and electron correlation on generalized oscillator strengths (GOS's) of endohedral atoms, A@C60, is theoretically studied choosing the Xe@C60 4d, 5s, and 5p fast electron impact ionization as the case study. Calculations are performed in the transferred to the atom energy region beyond the 4d threshold, ω=75–175 eV. T...
Article
Full-text available
It is demonstrated by the example of the Xe atom stuffed inside the C60 fullerene, that the so-called confinement resonances in 4d subshell strongly affect the photoionization cross-section of outer 5p and subvalent 5s electrons near 4d ionization threshold. It is a surprise that these narrow inner 4d shell resonances are not smeared out in the out...
Article
Photoionization cross sections for the outer shell of the nitrogen atom ground state are calculated in the single-particle Hartree–Fock approximation and, in order to take into account many-electron correlations, also in the Random Phase Approximation with Exchange (RPAE). To be able to apply the RPAE, its modification for the half-filled shell ato...
Article
Full-text available
It is demonstrated for the first time that in spite of well known big similarities between atomic ionization by photons and fast electrons, a qualitative difference exists in angular anisotropy parameters of electrons knocked out in these processes. The difference is disclosed here and attributed to distinction between normal (transverse) and virtu...
Article
Full-text available
We demonstrate that the angular distribution of electrons knocked out from an atom by a fast charge particle is determined not only by dipole but also by quadrupole transitions, the contribution of which can be considerably enhanced as compared to the case of photoionization. To obtain these matrix elements one has to study the angular distribution...
Article
Full-text available
The photoionization of a two-shell (“onion“) endohedral A@CN1@CN2 is considered. The effect of the fullerenes shells upon photoelectron from atom A is taken into account substituting the action of the fullerene by two zero-thickness “bubble potentials.“ The fullerenes shells polarization is included assuming that the radius of the outer shell R 2 i...
Article
Full-text available
The photoionization of a two-shell endohedral A@CN1@CN2 is considered. Formulas are presented for cross sections and angular anisotropy parameters, both dipole and nondipole. The effect of the fullerenes shell upon photoelectron from atom A is taken into account substituting the action of the fullerene by two zero-thickness “bubble potential.” The...
Article
We performed calculations of photoionization cross-section and other parameters characterizing this process for endohedrals consisting of C60 and located at the center inside noble gas atom and adjacent positive and negative ions. We have considered outer p- and s- subshells for the groups (F^-, Ne, Na^+), (Cl^-, Ar, K^+) and outer p- , s- and d- s...
Article
We developed a system of programs that permit to treat non-perturbatively the effect of the fullerene shell upon the stuffed atom photoelectrons in the frame of RPAE. We use the zero-thickness ``orange-skin'' potential. Usually this potential was applied to calculate a factor that permitted to obtain all photoionization characteristics of an endohe...