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Tytuł:
The Quasiparticle Electronic Energy Bands of the Cubic KMgF₃ Perovskite under Pressure Effect
Autorzy:
Syrotyuk, S.
Shved, V.
Klysko, Yu.
Powiązania:
https://bibliotekanauki.pl/articles/1030878.pdf
Data publikacji:
2018-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.15.Ap
71.15.Mb
71.15.Qe
Opis:
First-principles calculations have been carried out to study the electronic properties of the KMgF₃ perovskite crystal. On first stage the calculations were performed within the generalized gradient approximation. On the second stage we have evaluated the quasiparticle corrections to the generalized gradient approximation band structure. These significantly improved electronic energies have been found here for the first time on base of the quasiparticle approach as implemented in the ABINIT code. Also, the pressure dependent parameters of electronic energy band spectra were found in the generalized gradient approximation. For the first time the pressure dependent electronic band energies have been evaluated within the quasiparticle approach. The generalized gradient approximation band gap parameters are in good agreement with the literature data, obtained with local density approximation or generalized gradient approximation exchange-correlation functionals and are much underestimated compared with the experiment. The quasiparticle band gap agrees well with the measured value.
Źródło:
Acta Physica Polonica A; 2018, 133, 4; 990-993
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quantum Model for Metal-Insulator Transition in Amorphous Gd_{x}Si_{1-x}
Autorzy:
Paja, A.
Ornat, M.
Powiązania:
https://bibliotekanauki.pl/articles/1399304.pdf
Data publikacji:
2013-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.15.Cz
72.15.Lh
72.15.Rn
Opis:
The model for experimentally observed metal-insulator transition induced by magnetic field in amorphous $Gd_{x}Si_{1 - x}$ is presented. The method of calculation is based on the previously created model for amorphous alloys now developed to include magnetic field effects. The model is based on the quantum "2 $k_{F}$" scattering model theory where the pseudopotentials are replaced by the scattering matrix operators and the Fermi energy is properly determined by the accurate values of the phase shifts. The results agree very well with experimental data.
Źródło:
Acta Physica Polonica A; 2013, 124, 4; 717-719
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Effect of Hydrogenation on the Electrical Resistivity of Amorphous Alloys
Autorzy:
Ornat, M.
Paja, A.
Powiązania:
https://bibliotekanauki.pl/articles/1377805.pdf
Data publikacji:
2014-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.15.Cz
72.15.Qm
72.15.Rn
Opis:
Theoretical investigations of the influence of hydrogen contents on the electrical resistivity of amorphous metallic alloys have been carried out. We have made use of our method of calculations of the electrical resistivity of disordered systems based on the ground of Morgan-Howson-Saub and Evans models. Our method is fully quantum, includes multiple scattering effects and uses the scattering matrix operators for describing the electron-ion interactions. The model gives good agreement with experiment for many binary systems and should work for ternary systems as well, thus we performed calculations with hydrogen as one of the components of a ternary alloy. The results of our calculations show that the resistivity should increase with hydrogen concentration. Some experimental data confirm this predication.
Źródło:
Acta Physica Polonica A; 2014, 126, 6; 1296-1298
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Derivation of von Weizsäcker Equation Based οn Green-Gauss Theorem
Autorzy:
Romanowski, Z.
Krukowski, S.
Powiązania:
https://bibliotekanauki.pl/articles/1808100.pdf
Data publikacji:
2009-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
31.15.E-
71.15.Mb
71.15.Dx
Opis:
A simple and short derivation of von Weizsäcker equation for kinetic energy functional is presented. The derivation is based on the Green-Gauss theorem and is valid for one-electron systems. In the proof the asymptotic behavior of wave function for the finite systems was used. Two results important for kinetic energy functional evaluation are also derived as consequences of the Green-Gauss theorem.
Źródło:
Acta Physica Polonica A; 2009, 115, 3; 653-655
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spectroscopic parameters of neutral argon atom
Autorzy:
Salah, W.
Hassouneh, O.
Powiązania:
https://bibliotekanauki.pl/articles/1058748.pdf
Data publikacji:
2016-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
31.15.ag
31.15.aj
31.15.am
Opis:
We have calculated the spectroscopic data of the odd series nd [1/2]1 (3 ≤ n ≤ 9) of neutral argon atom relative to the ground level 3P⁶ ¹S₀ using a fully relativistic approach based on the Dirac equation. This series is one of three intermediate Rydberg series that converge to the first limit of ionization. The energy levels of this series are predicted. The obtained energy levels results are judged by comparing them with the experimental ones available in the literature. Within the uncertainty in the theoretical results, the agreement between our results and the experimental ones was found to be reasonable. Based on this agreement, the oscillator strengths f_{ij}, the radiative transition rates A_{ij}, the Landé g-factor, the magnetic dipole moment and the electric quadrupole hyperfine constants for the levels in question are calculated. The obtained results of f_{ij}, A_{ij}, and Landé g-factor are compared with the theoretical and experimental results published by other researchers where available as well as those published by NIST. Within the uncertainty in our results, a good agreement is found. Moreover, the studied levels are situated near and under the first limit of ionization where autoionization effects take place.
Źródło:
Acta Physica Polonica A; 2016, 130, 6; 1288-1294
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stable and Unstable Rovibrational States of a Molecule
Autorzy:
Konarski, J.
Powiązania:
https://bibliotekanauki.pl/articles/2011057.pdf
Data publikacji:
1999-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
33.15.-e
33.15.Dj
33.15.Mt
Opis:
Stability of motions for different potential functions describing vibrational motions of rotating molecule has been discussed. It was shown that an equilibrium position for nonrotating r$\text{}_{0}$ and rotating r$\text{}_{J}$ molecules for almost all the examined potentials is a node, but for the molecule described by the soft body model a critical value of rotation quantum number J$\text{}_{c}$ occurs above which r$\text{}_{0}$ is a saddle point, and the stable motion may occur only around r$\text{}_{J}$.
Źródło:
Acta Physica Polonica A; 1999, 96, 3-4; 353-357
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quantum Foundations of Resonant Recognition Model
Autorzy:
Keković, G.
Raković, D.
Tošić, B.
Davidović, D.
Cosić, I.
Powiązania:
https://bibliotekanauki.pl/articles/1537869.pdf
Data publikacji:
2010-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
87.14.E-
87.15.-v
87.15.B-
87.15.Cc
87.15.hp
87.15.kp
Opis:
Biomolecular recognition is an open scientific problem, which has been investigated in many theoretical and experimental aspects. In that sense, there are encouraging results within Resonant Recognition Model (RRM), based on the finding that there is a significant correlation between spectra of the numerical presentation of amino acids in the primary structure of proteins and their biological activity. It has been found through an extensive research that proteins with the same biological function have a common frequency in their numerical spectra. This frequency was found then to be a characteristic feature for protein biological function or interaction The RRM model proposes that the selectivity of protein interactions is based on resonant energy transfer between interacting biomolecules and that this energy, electromagnetic in its nature, is in the frequency range of $10^{13}$ to $10^{15}$ Hz, which incorporates infra-red (IR), visible and a small portion of the ultra-violet (UV) radiation. In this paper, the quantum mechanical basis of the RRM model will be investigated using the solution in the simplified framework of Hückel-like theory of molecular orbits.
Źródło:
Acta Physica Polonica A; 2010, 117, 5; 756-759
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of the Direct Coulomb Interactions on the Resistivity in NdPb$\text{}_{3}$
Autorzy:
Sławiński, P.
Kletowski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1929856.pdf
Data publikacji:
1994-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.15.Eb
72.15.Qm
Opis:
In order to investigate the influence of the 4f electrons on the scattering processes we measured resistivity of the NdPb$\text{}_{3}$ in the temperature range 7-300 K. As a result, we could compare the experimentally determined magnetic contribution to the resistivity with the theoretically calculated ones for the exchange and quadrupolar scattering. The results may confirm that the direct Coulomb interactions between 4f and conduction electrons predominate.
Źródło:
Acta Physica Polonica A; 1994, 85, 2; 283-286
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Enhanced Thermoelectric Power Factors in the Ce(Ni_{1-x}Cu_{x})₂Si₂ and CeNi₂(Si_{1-y}Ge_{y})₂ Alloys
Autorzy:
Synoradzki, K.
Toliński, T.
Koterlyn, M.
Powiązania:
https://bibliotekanauki.pl/articles/1029766.pdf
Data publikacji:
2018-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.15.Eb
72.15.Jf
Opis:
In the presence of hybridization of the f states with the conduction electrons Ce-based compounds can show large peaks in the temperature dependence of the Seebeck coefficient, which makes them interesting materials for applications. The Seebeck coefficient and electrical resistivity of the bulk, arc-melted, single phase samples of Ce(Ni_{1-x}Cu_{x})₂Si₂ and CeNi₂(Si_{1-y}Ge_{y})₂ alloys were measured over the temperature range of 2 K to 300 K. All the samples exhibited a positive Seebeck coefficient, which reaches up to ım50μV/K at 150 K and it can be shifted up to 300 K by appropriate doping. The thermoelectric power factor, PF = S²/ρ, reached a maximum of 1.4×10¯³ Wm¯¹K¯² at 290 K and 1.1×10¯³ Wm¯¹K¯² at 110 K for x=0.25 and y=0.75, respectively. For selected representatives of the studied series thermoelectric properties have been measured up to 1000 K.
Źródło:
Acta Physica Polonica A; 2018, 133, 3; 366-368
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Computational Study on (E)-3-(2-Chlorostyryl)-5,5-Dimethylcyclohex-2-Enone
Autorzy:
Eryilmaz, S.
Gül, M.
Kozak, Z.
İnkaya, E.
Powiązania:
https://bibliotekanauki.pl/articles/1031251.pdf
Data publikacji:
2017-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
31.15.E
31.15.es
Opis:
A new isophorone derivative, (E)-3-(2-chlorostyryl)-5,5-dimethylcyclohex-2-enone, was synthesized by aldol reactions and characterized by single crystal diffraction method to determine the molecular structure. The computational analysis based on density functional theory with Becke's three-parameter hybrid functional was carried out using Lee, Yang and Parr correlation functional (B3LYP)/6-311++G(d,p), to investigate the structural parameters, the values of dipole moment, the total polarizability, the first-order hyperpolarizability for the non-linear optical behaviour and the thermodynamic parameters at different temperatures of the compound.
Źródło:
Acta Physica Polonica A; 2017, 132, 3; 738-741
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Use of Guseinovs One-Center Expansion Formulae and Löwdin α Radial Function in Calculation of Two-Center Overlap Integrals over Slater Type Orbitals with Noninteger Principal Quantum Numbers
Autorzy:
Mamedov, B.
Çopuroğlu, E.
Powiązania:
https://bibliotekanauki.pl/articles/1505335.pdf
Data publikacji:
2011-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
31.15.-p
31.15.ae
Opis:
An efficient calculation algorithm is presented for two-center overlap integrals over noninteger n* Slater type orbitals in molecular coordinate system based on the use of Guseinov's one-center expansion formulae and Löwdin α radial function. These integrals are expressed in terms of overlap integrals of integer n Slater type orbitals. The analytical formulae offer the advantage of direct and efficient calculation of the two-center overlap integrals over noninteger n* Slater type orbitals without the use of numerical methods. Several numerical results obtained are presented to demonstrate the improvements in convergence rates.
Źródło:
Acta Physica Polonica A; 2011, 119, 3; 332-335
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Local Environment on the Electronic Structure and Magnetic Properties of Ni$\text{}_{1-x}$Cu$\text{}_{x}$MnSb Alloys
Autorzy:
Jezierski, A.
Szytuła, A.
Powiązania:
https://bibliotekanauki.pl/articles/2013241.pdf
Data publikacji:
2000-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
31.15.Ar
31.15.Ew
71.15.Mb
71.15.-m
71.15.La
71.20.-b
71.20.Be
Opis:
The magnetic ordering in Ni$\text{}_{1-x}$Cu$\text{}_{x}$MnSb alloys changes from ferromagnetic (x=0) to antiferromagnetic (x=1). The X-ray and neutron diffraction showed that the systems crystallise in C1$\text{}_{b}$ type structure. We present an influence of the local chemical ordering on the electronic and magnetic properties of Ni$\text{}_{1-x}$Cu$\text{}_{x}$MnSb alloys. The band structure and the magnetic moments were calculated by the spin-polarised linear muffin-tin orbital in the atomic sphere approximation method for the experimental values of the lattice parameters. The magnetic moment of Mn increases from 3.8 μ$\text{}_{B}$ for x=0 to 4.18 μ$\text{}_{B}$ for x=1.
Źródło:
Acta Physica Polonica A; 2000, 97, 3; 607-610
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Unusual Electron Transport Properties of $U_{0.05}Y_{0.95}Al_2$
Autorzy:
Tran, V.
Powiązania:
https://bibliotekanauki.pl/articles/1813710.pdf
Data publikacji:
2008-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.15.Jf
72.15.Qm
Opis:
We report a detailed study of the resistivity (ρ(T)) and thermoelectric power (S(T)) of the alloy $U_{0.05}Y_{0.95}Al_2$, which crystallises in the cubic $MgCu_2$-type structure. The resistivity is found to follow ρ(T) ∝ ln T between 15 and 40 K and a quasi-linear temperature dependence $-T^{1.16}$ for T <10 K. At a magnetic field of 9 T a Kondo-type maximum occurs in the resistivity data at 7 K, below which the Fermi liquid behaviour (ρ(T) ∝ $T^2$) is recovered. S(T)/T shows a $T^{0.5}$ power law for T <12 K. The low-temperature unconventional features observed in $U_{0.05}Y_{0.95}Al_2$ are presumably due to the presence of the two-channel Kondo effect.
Źródło:
Acta Physica Polonica A; 2008, 113, 1; 387-390
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Overlapping Muffin-Tin Approximation
Autorzy:
Zwierzycki, M.
Andersen, O.
Powiązania:
https://bibliotekanauki.pl/articles/1810287.pdf
Data publikacji:
2009-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.15.-m
71.15.Ap
Opis:
We present the formalism and demonstrate the use of the overlapping muffin-tin approximation. This fits a full potential to a superposition of spherically symmetric short-ranged potential wells plus a constant. For one-electron potentials of this form, the standard multiple-scattering methods can solve Schrödingers' equation correctly to 1st order in the potential overlap. Choosing an augmented-plane-wave method as the source of the full potential, we illustrate the procedure for diamond-structured Si. First, we compare the potential in the Si-centered overlapping muffin-tin approximation with the full potential, and then compare the corresponding overlapping muffin-tin approximation N-th order muffin-tin orbital and full-potential linear augmented plane wave band structures. We find that the two latter agree qualitatively for a wide range of overlaps and that the valence bands have a root mean squared deviation of 20 meV/electron for 30% radial overlap. Smaller overlaps give worse potentials and larger overlaps give larger 2nd-order errors of the multiple-scattering method. To further remove the mean error of the bands for small overlaps is simple.
Źródło:
Acta Physica Polonica A; 2009, 115, 1; 64-68
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Choice of Pseudopotential and Electroresistance of Simple Disordered Metals
Autorzy:
Shvets, V. T.
Belov, E. V.
Powiązania:
https://bibliotekanauki.pl/articles/2011163.pdf
Data publikacji:
1999-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.15.Hx
72.15.Cz
Opis:
An expression is investigated for inverse relaxation time for electroconductivity in the simple disordered metals within a framework of a kinetic equation method and a perturbation theory by the powers of a pseudopotential of electron-ion interaction. Numerical calculation of the third-order term by a pseudopotential for inverse relaxation time of 25 simple disordered metals is carried out. Three different model local pseudopotentials are used. Strong relation of the results of calculation between the choice of a model pseudopotential and concrete values of the pseudopotential parameters is found out for all metals. Selection criterions for the model pseudopotentials are formulated.
Źródło:
Acta Physica Polonica A; 1999, 96, 6; 741-750
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł

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