Jacek Bieroń | Jagiellonian University in Krakow (original) (raw)
Papers by Jacek Bieroń
Physical Review A
The relativistic multiconfiguration Dirac-Hartree-Fock and the nonrelativistic multiconfiguration... more The relativistic multiconfiguration Dirac-Hartree-Fock and the nonrelativistic multiconfiguration Hartree-Fock methods have been employed to calculate the magnetic dipole and electric quadrupole hyperfine structure constants of zinc. The calculated electric field gradients for the 4s4p 3 P o 1 and 4s4p 3 P o 2 states, together with experimental values of the electric quadrupole hyperfine structure constants, made it possible to extract a nuclear electric quadrupole moment Q(67 Zn) = 0.122(10) b. The error bar was evaluated in a quasistatistical approach-the calculations were carried out with 11 different methods, and then the error bar was estimated from the differences between the results obtained with those methods.
Physical Review A
The multiconfiguration Dirac-Hartree-Fock method is employed to calculate the continuum electron ... more The multiconfiguration Dirac-Hartree-Fock method is employed to calculate the continuum electron wave functions, which are then used to estimate their contribution to the atomic electric dipole moment (EDM) of 129 Xe. The EDM arises from (P , T)-odd electron-nucleon tensor-pseudotensor and pseudoscalar-scalar interactions, the nuclear Schiff moment, the interaction of the electron electric dipole moment with nuclear magnetic moments, and atomic electric dipole matrix elements. In addition to being estimated in the continuum states, all of these interactions are also estimated in the ground state, as well as in the Rydberg states of 129 Xe. Calculations of one-electron atomic orbitals include the interelectronic interactions, through valence and core-valence electron correlation effects. The contribution to the EDM from continuum states is found to be of the same order of magnitude as the contribution from discrete states.
Physical Review A, 2016
The multiconfiguration Dirac-Hartree-Fock (MCDHF) method was employed to calculate atomic electri... more The multiconfiguration Dirac-Hartree-Fock (MCDHF) method was employed to calculate atomic electric dipole moments (EDM) of the superheavy element copernicium (Cn, Z = 112). The EDM enhancement factors of Cn, here calculated for the first time, are about one order of magnitude larger than those of Hg. The exponential dependence of enhancement factors on atomic number Z along group 12 of the periodic table was derived from the EDMs of the entire homolog series, 69 30 Zn, 111 48 Cd, 199 80 Hg, 285 112 Cn, and 482 162 Uhb. These results show that superheavy elements with sufficiently large half-lives are good candidates for EDM searches.
The European Physical Journal D, 2015
Hyperfine structure A and B factors of the atomic 5s 5p 3 P2 → 5s 6s 3 S1 transition are determin... more Hyperfine structure A and B factors of the atomic 5s 5p 3 P2 → 5s 6s 3 S1 transition are determined from collinear laser spectroscopy data of 107−123 Cd and 111m−123m Cd. Nuclear magnetic moments and electric quadrupole moments are extracted using reference dipole moments and calculated electric field gradients, respectively. The hyperfine structure anomaly for isotopes with s1 /2 and d5 /2 nuclear ground states and isomeric h11 /2 states is evaluated and a linear relationship is observed for all nuclear states except s1 /2. This corresponds to the Moskowitz-Lombardi rule that was established in the mercury region of the nuclear chart but in the case of cadmium the slope is distinctively smaller than for mercury. In total four atomic and ionic levels were analyzed and all of them exhibit a similar behaviour. The electric field gradient for the atomic 5s 5p 3 P2 level is derived from multi-configuration Dirac-Hartree-Fock calculations in order to evaluate the spectroscopic nuclear quadrupole moments. The results are consistent with those obtained in an ionic transition and based on a similar calculation.
Atomic Physics at Accelerators: Mass Spectrometry, 2001
We present recent results in the field of total binding energy calculations, Landé factors, quant... more We present recent results in the field of total binding energy calculations, Landé factors, quantum electrodynamics corrections and lifetime that are of interest for ion traps and ion sources. We describe in detail MCDF and RMBPT calculation of ionic binding energies, which are needed for the determination of atomic masses from highly charged ion measurements. We also show new results concerning Landé factor in 3-electron ions. Finally we describe how relativistic calculations can help understand the physics of heavy ion production ion sources.
Journal of Research of the National Institute of Standards and Technology, 1997
Abstract Electron-impact total ionization cross sections for the CH radical and C 2 H 2 (acetylen... more Abstract Electron-impact total ionization cross sections for the CH radical and C 2 H 2 (acetylene) have been calculated using the Binary-Encounter-Bethe (BEB) model. The BEB model combines the Mott cross section and the asymptotic form of the Bethe theory, and ...
Theoretical Chemistry Accounts, 2011
We explore QED and many-body effects in superheavy elements up to Z = 173 using the multiconfigur... more We explore QED and many-body effects in superheavy elements up to Z = 173 using the multiconfiguration Dirac-Fock method. We study the effect of going beyond the average-level approximation on the determination of the ground state of element 140, and compare with the recent work of Pekka Pyykkö on the periodic table for super heavy elements[1]. We confirm that QED corrections are of the order of 1% on ionization energies. We show that the atomic number at which the 1s shell dives into the negative energy continuum is 173, and is not affected by the approximation employed to evaluate the electron-electron interaction.
Physical Review Letters, 2001
Calculations with the linearized augmented plane wave method indicate that several high-density f... more Calculations with the linearized augmented plane wave method indicate that several high-density forms of sulfur trioxide should be accessible at pressures above 29 GPa, with densities up to 1.7 times larger than the presently known forms of solid SO 3. Exotic high-pressure modifications of common substances are interesting, the quartz-like CO 2 being a striking example. 1 We now consider SO 3 , based on the simple idea of letting the coordination number of sulfur, CN(S), grow from the values of three or four in the known oligomeric or polymeric modifications of SO 3 to the equally common value CN(S) = 6, as in SF 6 , and at the same time imposing for all oxygens CN(O) = 2. The solid-state calculations were performed with the fullpotential linearized augmented plane-wave (LAPW) method, as implemented in the Wien97 2 software. Technical details of the calculations are available in the electronic supplementary material. † The volume of the unit cell, the ratio between the edges of the unit cell, and the atomic positions inside the cell were successively optimized until convergence was achieved. Two systems were studied for energetic reference. One was the SO 3 molecule in D 3h configuration, placed onto a hexagonal grid with 529 pm (10 a.u.) unit vectors in all directions. The SO bond lengths were optimized while the size of unit cell was not. This rather artificial system ('fluid') gives a rough estimate of the energy of gaseous SO 3 in the framework of the present computational model. The other reference system chosen was the polymeric b-SO 3 in the experimental structure. 3 This modification of SO 3 consists of parallel spiral chains, which are not chemically bonded to each other (Fig. 1(a)). The structure of an unknown crystalline solid can in general not be predicted. We used analogies with other systems of similar composition (AB 3) or chemical intuition as starting points for the calculation. For choice of the model structures we set the requirement that the sulfur must be hexa-coordinated and the oxygen, two-coordinated. The possible structures of connected octahedra are numerous, 4 and the following three ones, relatively simple to model, were chosen. The first structure which we considered was a simple cubic one of the ReO 3 type (space group Pm3m, no. 221). This structure was chosen based on the isoelectronic principle: SO 3 and AlF 3 differ only in nuclear charges, both containing 40 electrons per formula unit, and AlF 3 has a high-temperature phase with this structure. 5 There is one important difference between fluorine and oxygen, however: while fluorine in the AlF 3 structure is primarily ionic, with little preference in bond directionality, the oxygen atoms are expected to form covalent bonds, ideally at bond angle, q o = 109.5°. In siloxanes or silicates q o can be much larger. The ReO 3 structure imposes q o = 180°. The structure can be visualized as a simple cubic arrangement of S atoms, with O atoms located in the middle of each nearest-neighbour pair (Fig. 1(b)).
Physical Review A, 2005
ABSTRACT
Physical Review A, 2005
ABSTRACT
Physical Review A, 2001
ABSTRACT
Physical Review A, 1999
ABSTRACT The hyperfine constants for the ground states of Be+ and F6+, and for the two lowest exc... more ABSTRACT The hyperfine constants for the ground states of Be+ and F6+, and for the two lowest excited states of Be+, are calculated in a multiconfiguration Dirac-Fock model. Convergence of the calculated magnetic dipole constants is studied as the active set of orbitals is systematically increased. The final results are compared with experimental data and theoretical values obtained from other methods.
Physical Review A, 1999
Large-scale multiconfigurational Dirac-Fock calculations of the hyperfine-structure constants and... more Large-scale multiconfigurational Dirac-Fock calculations of the hyperfine-structure constants and determination of the nuclear quadrupole moment of 49 Ti. Jacek Bieroń * Instytut Fizyki imienia Mariana Smoluchowskiego, Uniwersytet ...
Physical Review A, 1995
The multiconfiguration Dirac-Fock model is employed to study the effects of relativity and electr... more The multiconfiguration Dirac-Fock model is employed to study the effects of relativity and electron correlation on the hyperfine interaction constants of the 3d2 3P1, 3P2, 1D2, and 3F2 levels of Sc+ and the 4d2 3P1 level of Y+. The wave function expansions are obtained with the active space method, where configuration state functions of a specific parity and J value
Physical Review A, 1998
A theoretical model for electron-impact ionization cross section has been applied to Rb and the t... more A theoretical model for electron-impact ionization cross section has been applied to Rb and the theoretical cross section (from the threshold to 1 keV in incident energy) is in good agreement with the recent experimental data obtained using Rb atoms trapped in a magneto-optical trap. The theoretical model, called the binary-encounter-dipole (BED) model, combines a modified Mott cross section with
Physical Review A, 1997
Nuclear quadrupole moment of scandium. Jacek Bieroń and Ian P. Grant Mathematical Institute, Univ... more Nuclear quadrupole moment of scandium. Jacek Bieroń and Ian P. Grant Mathematical Institute, University of Oxford, 24-29 St. Giles, Oxford OX1 3LB, United Kingdom. Charlotte Froese Fischer Department of Computer Science ...
Physica Scripta, 2001
The determination of atomic masses from highly ionized atoms using Penning Traps requires precise... more The determination of atomic masses from highly ionized atoms using Penning Traps requires precise values for electronic binding energies. In the present work, binding energies of several ions (from several elements) are calculated in the framework of two relativistic many-body methods: Relativistic Many-Body Perturbation Theory (RMBPT) and Multi-Con¢guration DiracF ock (MCDF). The ions studied in this work are: Cl (He and Li-like), Se (F and Ne-like), Cs (He, Be, Ne, Al, Cl, Ar, K, Kr, Xe-like and neutral Cs), Hg, Pb and U (Br and Kr-like). Some of them are presented in this paper. Cesium has been treated in more details, allowing for a systematic comparison between MCDF and RMBPT methods. The Cs ions binding energies allow for the determination of atomic Cs mass, which can be used in a QED-independent ¢ne structure constant determination.
Physical Review A
The relativistic multiconfiguration Dirac-Hartree-Fock and the nonrelativistic multiconfiguration... more The relativistic multiconfiguration Dirac-Hartree-Fock and the nonrelativistic multiconfiguration Hartree-Fock methods have been employed to calculate the magnetic dipole and electric quadrupole hyperfine structure constants of zinc. The calculated electric field gradients for the 4s4p 3 P o 1 and 4s4p 3 P o 2 states, together with experimental values of the electric quadrupole hyperfine structure constants, made it possible to extract a nuclear electric quadrupole moment Q(67 Zn) = 0.122(10) b. The error bar was evaluated in a quasistatistical approach-the calculations were carried out with 11 different methods, and then the error bar was estimated from the differences between the results obtained with those methods.
Physical Review A
The multiconfiguration Dirac-Hartree-Fock method is employed to calculate the continuum electron ... more The multiconfiguration Dirac-Hartree-Fock method is employed to calculate the continuum electron wave functions, which are then used to estimate their contribution to the atomic electric dipole moment (EDM) of 129 Xe. The EDM arises from (P , T)-odd electron-nucleon tensor-pseudotensor and pseudoscalar-scalar interactions, the nuclear Schiff moment, the interaction of the electron electric dipole moment with nuclear magnetic moments, and atomic electric dipole matrix elements. In addition to being estimated in the continuum states, all of these interactions are also estimated in the ground state, as well as in the Rydberg states of 129 Xe. Calculations of one-electron atomic orbitals include the interelectronic interactions, through valence and core-valence electron correlation effects. The contribution to the EDM from continuum states is found to be of the same order of magnitude as the contribution from discrete states.
Physical Review A, 2016
The multiconfiguration Dirac-Hartree-Fock (MCDHF) method was employed to calculate atomic electri... more The multiconfiguration Dirac-Hartree-Fock (MCDHF) method was employed to calculate atomic electric dipole moments (EDM) of the superheavy element copernicium (Cn, Z = 112). The EDM enhancement factors of Cn, here calculated for the first time, are about one order of magnitude larger than those of Hg. The exponential dependence of enhancement factors on atomic number Z along group 12 of the periodic table was derived from the EDMs of the entire homolog series, 69 30 Zn, 111 48 Cd, 199 80 Hg, 285 112 Cn, and 482 162 Uhb. These results show that superheavy elements with sufficiently large half-lives are good candidates for EDM searches.
The European Physical Journal D, 2015
Hyperfine structure A and B factors of the atomic 5s 5p 3 P2 → 5s 6s 3 S1 transition are determin... more Hyperfine structure A and B factors of the atomic 5s 5p 3 P2 → 5s 6s 3 S1 transition are determined from collinear laser spectroscopy data of 107−123 Cd and 111m−123m Cd. Nuclear magnetic moments and electric quadrupole moments are extracted using reference dipole moments and calculated electric field gradients, respectively. The hyperfine structure anomaly for isotopes with s1 /2 and d5 /2 nuclear ground states and isomeric h11 /2 states is evaluated and a linear relationship is observed for all nuclear states except s1 /2. This corresponds to the Moskowitz-Lombardi rule that was established in the mercury region of the nuclear chart but in the case of cadmium the slope is distinctively smaller than for mercury. In total four atomic and ionic levels were analyzed and all of them exhibit a similar behaviour. The electric field gradient for the atomic 5s 5p 3 P2 level is derived from multi-configuration Dirac-Hartree-Fock calculations in order to evaluate the spectroscopic nuclear quadrupole moments. The results are consistent with those obtained in an ionic transition and based on a similar calculation.
Atomic Physics at Accelerators: Mass Spectrometry, 2001
We present recent results in the field of total binding energy calculations, Landé factors, quant... more We present recent results in the field of total binding energy calculations, Landé factors, quantum electrodynamics corrections and lifetime that are of interest for ion traps and ion sources. We describe in detail MCDF and RMBPT calculation of ionic binding energies, which are needed for the determination of atomic masses from highly charged ion measurements. We also show new results concerning Landé factor in 3-electron ions. Finally we describe how relativistic calculations can help understand the physics of heavy ion production ion sources.
Journal of Research of the National Institute of Standards and Technology, 1997
Abstract Electron-impact total ionization cross sections for the CH radical and C 2 H 2 (acetylen... more Abstract Electron-impact total ionization cross sections for the CH radical and C 2 H 2 (acetylene) have been calculated using the Binary-Encounter-Bethe (BEB) model. The BEB model combines the Mott cross section and the asymptotic form of the Bethe theory, and ...
Theoretical Chemistry Accounts, 2011
We explore QED and many-body effects in superheavy elements up to Z = 173 using the multiconfigur... more We explore QED and many-body effects in superheavy elements up to Z = 173 using the multiconfiguration Dirac-Fock method. We study the effect of going beyond the average-level approximation on the determination of the ground state of element 140, and compare with the recent work of Pekka Pyykkö on the periodic table for super heavy elements[1]. We confirm that QED corrections are of the order of 1% on ionization energies. We show that the atomic number at which the 1s shell dives into the negative energy continuum is 173, and is not affected by the approximation employed to evaluate the electron-electron interaction.
Physical Review Letters, 2001
Calculations with the linearized augmented plane wave method indicate that several high-density f... more Calculations with the linearized augmented plane wave method indicate that several high-density forms of sulfur trioxide should be accessible at pressures above 29 GPa, with densities up to 1.7 times larger than the presently known forms of solid SO 3. Exotic high-pressure modifications of common substances are interesting, the quartz-like CO 2 being a striking example. 1 We now consider SO 3 , based on the simple idea of letting the coordination number of sulfur, CN(S), grow from the values of three or four in the known oligomeric or polymeric modifications of SO 3 to the equally common value CN(S) = 6, as in SF 6 , and at the same time imposing for all oxygens CN(O) = 2. The solid-state calculations were performed with the fullpotential linearized augmented plane-wave (LAPW) method, as implemented in the Wien97 2 software. Technical details of the calculations are available in the electronic supplementary material. † The volume of the unit cell, the ratio between the edges of the unit cell, and the atomic positions inside the cell were successively optimized until convergence was achieved. Two systems were studied for energetic reference. One was the SO 3 molecule in D 3h configuration, placed onto a hexagonal grid with 529 pm (10 a.u.) unit vectors in all directions. The SO bond lengths were optimized while the size of unit cell was not. This rather artificial system ('fluid') gives a rough estimate of the energy of gaseous SO 3 in the framework of the present computational model. The other reference system chosen was the polymeric b-SO 3 in the experimental structure. 3 This modification of SO 3 consists of parallel spiral chains, which are not chemically bonded to each other (Fig. 1(a)). The structure of an unknown crystalline solid can in general not be predicted. We used analogies with other systems of similar composition (AB 3) or chemical intuition as starting points for the calculation. For choice of the model structures we set the requirement that the sulfur must be hexa-coordinated and the oxygen, two-coordinated. The possible structures of connected octahedra are numerous, 4 and the following three ones, relatively simple to model, were chosen. The first structure which we considered was a simple cubic one of the ReO 3 type (space group Pm3m, no. 221). This structure was chosen based on the isoelectronic principle: SO 3 and AlF 3 differ only in nuclear charges, both containing 40 electrons per formula unit, and AlF 3 has a high-temperature phase with this structure. 5 There is one important difference between fluorine and oxygen, however: while fluorine in the AlF 3 structure is primarily ionic, with little preference in bond directionality, the oxygen atoms are expected to form covalent bonds, ideally at bond angle, q o = 109.5°. In siloxanes or silicates q o can be much larger. The ReO 3 structure imposes q o = 180°. The structure can be visualized as a simple cubic arrangement of S atoms, with O atoms located in the middle of each nearest-neighbour pair (Fig. 1(b)).
Physical Review A, 2005
ABSTRACT
Physical Review A, 2005
ABSTRACT
Physical Review A, 2001
ABSTRACT
Physical Review A, 1999
ABSTRACT The hyperfine constants for the ground states of Be+ and F6+, and for the two lowest exc... more ABSTRACT The hyperfine constants for the ground states of Be+ and F6+, and for the two lowest excited states of Be+, are calculated in a multiconfiguration Dirac-Fock model. Convergence of the calculated magnetic dipole constants is studied as the active set of orbitals is systematically increased. The final results are compared with experimental data and theoretical values obtained from other methods.
Physical Review A, 1999
Large-scale multiconfigurational Dirac-Fock calculations of the hyperfine-structure constants and... more Large-scale multiconfigurational Dirac-Fock calculations of the hyperfine-structure constants and determination of the nuclear quadrupole moment of 49 Ti. Jacek Bieroń * Instytut Fizyki imienia Mariana Smoluchowskiego, Uniwersytet ...
Physical Review A, 1995
The multiconfiguration Dirac-Fock model is employed to study the effects of relativity and electr... more The multiconfiguration Dirac-Fock model is employed to study the effects of relativity and electron correlation on the hyperfine interaction constants of the 3d2 3P1, 3P2, 1D2, and 3F2 levels of Sc+ and the 4d2 3P1 level of Y+. The wave function expansions are obtained with the active space method, where configuration state functions of a specific parity and J value
Physical Review A, 1998
A theoretical model for electron-impact ionization cross section has been applied to Rb and the t... more A theoretical model for electron-impact ionization cross section has been applied to Rb and the theoretical cross section (from the threshold to 1 keV in incident energy) is in good agreement with the recent experimental data obtained using Rb atoms trapped in a magneto-optical trap. The theoretical model, called the binary-encounter-dipole (BED) model, combines a modified Mott cross section with
Physical Review A, 1997
Nuclear quadrupole moment of scandium. Jacek Bieroń and Ian P. Grant Mathematical Institute, Univ... more Nuclear quadrupole moment of scandium. Jacek Bieroń and Ian P. Grant Mathematical Institute, University of Oxford, 24-29 St. Giles, Oxford OX1 3LB, United Kingdom. Charlotte Froese Fischer Department of Computer Science ...
Physica Scripta, 2001
The determination of atomic masses from highly ionized atoms using Penning Traps requires precise... more The determination of atomic masses from highly ionized atoms using Penning Traps requires precise values for electronic binding energies. In the present work, binding energies of several ions (from several elements) are calculated in the framework of two relativistic many-body methods: Relativistic Many-Body Perturbation Theory (RMBPT) and Multi-Con¢guration DiracF ock (MCDF). The ions studied in this work are: Cl (He and Li-like), Se (F and Ne-like), Cs (He, Be, Ne, Al, Cl, Ar, K, Kr, Xe-like and neutral Cs), Hg, Pb and U (Br and Kr-like). Some of them are presented in this paper. Cesium has been treated in more details, allowing for a systematic comparison between MCDF and RMBPT methods. The Cs ions binding energies allow for the determination of atomic Cs mass, which can be used in a QED-independent ¢ne structure constant determination.