Empirical formula for mass excess of heavy and superheavy nuclei

2016 ◽  
Vol 31 (28) ◽  
pp. 1650162 ◽  
Author(s):  
H. C. Manjunatha ◽  
B. M. Chandrika ◽  
L. Seenappa
Keyword(s):  
Empirical Formula ◽  
Superheavy Nuclei ◽  
Mass Excess ◽  
Hartree Fock ◽  
Heavy And Superheavy Nuclei ◽  
Polynomial Fit ◽  
Calculated Mass ◽  
Model Independent ◽  
Experimental Values ◽  
Good Agreement

A new empirical formula is proposed for mass excess of heavy and superheavy nuclei in the region Z = 96–129. The parameters of the formula are obtained by making a polynomial fit to the available theoretical and experimental data. The calculated mass excess values are compared with the experimental values and other results of the earlier proposed models such as finite range droplet model (FRDM) and Hartree–Fock–Bogoliubov (HFB) method. Standard deviation of calculated mass excess values for each atomic number is tabulated. The good agreement of present formula with the experiment and other models suggests that the present formula could be used to evaluate the mass excess values of heavy and superheavy nuclei in the region 96[Formula: see text][Formula: see text][Formula: see text]Z[Formula: see text][Formula: see text][Formula: see text]129. This formula is a model-independent formula and is first of its kind that produces a mass excess values with the only simple inputs of only Z and A.

scholarly journals Current Status and Developments of the Atomic Database on Rare-Earths at Mons University (DREAM)

Atoms ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 18 ◽  
Author(s):  
Pascal Quinet ◽  
Patrick Palmeri
Keyword(s):  
Rare Earths ◽  
Spectral Lines ◽  
Oscillator Strengths ◽  
Current Status ◽  
Time Resolved ◽  
Hartree Fock ◽  
Lanthanide Atoms ◽  
Experimental Values ◽  
Theoretical Results ◽  
Good Agreement

The main purpose of the Database on Rare Earths At Mons University (DREAM) is to provide the scientific community with updated spectroscopic parameters related to lanthanide atoms (Z = 57–71) in their lowest ionization stages. The radiative parameters (oscillator strengths and transitions probabilities) listed in the database have been obtained over the past 20 years by the Atomic Physics and Astrophysics group of Mons University, Belgium, thanks to a systematic and extensive use of the pseudo-relativistic Hartree-Fock (HFR) method modified for taking core-polarization and core-penetration effects into account. Most of these theoretical results have been validated by the good agreement obtained when comparing computed radiative lifetimes and accurate experimental values measured by the time-resolved laser-induced fluorescence technique. In the present paper, we report on the current status and developments of the database that gathers radiative parameters for more than 72,000 spectral lines in neutral, singly-, doubly-, and triply-ionized lanthanides.

EFFECT OF TENSOR INTERACTION ON HEAVY AND SUPERHEAVY NUCLEI

2010 ◽  
Vol 25 (21n23) ◽  
pp. 1809-1813 ◽  
Author(s):  
XIAN-RONG ZHOU ◽  
HIROYUKI SAGAWA
Keyword(s):  
Single Particle ◽  
Shell Structure ◽  
Spherical Shape ◽  
Tensor Interaction ◽  
Superheavy Nuclei ◽  
Hartree Fock ◽  
Heavy And Superheavy Nuclei ◽  
Large Shell ◽  
Particle Spectra ◽  
Shell Gaps

The effect of tensor interaction is discussed on the deformation and the shell structure of heavy and superheavy nuclei within the deformed Skyrme Hartree-Fock+BCS model. The importance of the tensor correlations is shown for the single particle spectra of protons in 249 Bk . The large shell gaps of superheavy nuclei are found at Z = 114 and Z = 120 for protons and N = 184 for neutrons with the spherical shape irrespective of the tensor correlations. It is also shown that Z = 114 and N = 164 shell gaps are more pronounced by the tensor correlations in the case of SLy 5+ T interaction.

scholarly journals Interpretation of the spectrum of Pb(II). Theoretical transition probabilities and lifetimes

2001 ◽  
Vol 79 (7) ◽  
pp. 999-1009 ◽  
Author(s):  
C Colón ◽  
A Alonso-Medina
Keyword(s):  
Transition Probabilities ◽  
Energy Levels ◽  
Radiative Transition ◽  
Least Square ◽  
Large Contribution ◽  
Hartree Fock ◽  
Forbidden Transition ◽  
Method Of Least Square ◽  
Experimental Values ◽  
Good Agreement

Radiative transition probabilities for 190 lines arising from the ns 2S1/2, np 2P1/2,3/2, nd 2D3/2,5/2, nf 2F5/2,7/2, and 6p2 (4P1/2,3/2,5/2, 2D3/2,5/2, 2P1/2,3/2, and 2S1/2) levels of Pb(II) have been calculated. Lifetimes of the above mentioned levels have been determined from the present transition probabilities. These values were obtained in intermediate coupling (IC) and using ab initio relativistic Hartree-Fock calculations. For the IC calculations, we use the standard method of least-square fitting of experimental energy levels by means of computer codes from Cowan. The results of calculations for radiative transition probabilities and excited states lifetimes are presented and compared with the experimental results present in the literature and with other theoretical values. There is generally good agreement between our values and the experimental data available. Analysis of the interaction shows that the level 4P5/2 of the 6s6p2 configuration presents a large contribution to the 2D5/2 level of the 6s26d configuration. This result explains the good agreement between our result and the experimental values obtained to the observed as the 6s6p2 4P5/2 – 6s 25f2F7/2 dipole-forbidden transition. PACS Nos.: 32.70^*, 32.70Fw, 32.70Cs

scholarly journals Transition spectral parameters of In-like Ba, La and Ce ions

2021 ◽  
Author(s):  
Miao Wu ◽  
Zhencen He
Keyword(s):  
Quantum Electrodynamics ◽  
Transition Probabilities ◽  
Energy Levels ◽  
Oscillator Strengths ◽  
Spectral Parameters ◽  
Hartree Fock ◽  
Experimental Values ◽  
Theoretical Results ◽  
Good Agreement ◽  
Line Strengths

The spectral parameters (energy levels, wavelengths, transition probabilities, line strengths and oscillator strengths) of resonance lines for Ba VIII, La IX and Ce X have been performed using the multiconfiguration Dirac-Hartree-Fock method, the contributions of quantum electrodynamics and Breit interactions correction are taken into considered. The calculated results of energy levels and wavelengths are in good agreement with experimental values and other calculation. The number of energy levels and wavelengths considered is larger than that of any other experiment values and other calculations. The transition probabilities, line strengths and oscillator strengths are also calculated where no other theoretical results and experimental values are available.

scholarly journals QMC Calculations of Total Energy and Bond Length of Some Polyatomic Organic Molecules

2016 ◽  
Vol 64 ◽  
pp. 63-68
Author(s):  
Sylvester A. Ekong ◽  
David A. Oyegoke
Keyword(s):  
Wave Function ◽  
Total Energy ◽  
Quantum Monte Carlo ◽  
Organic Molecules ◽  
Linus Pauling ◽  
Hartree Fock ◽  
Total Energies ◽  
Experimental Values ◽  
Significant Figures ◽  
Good Agreement

This paper aims at determining the total energy and bond lengths of some polyatomic organic molecules, using quantum Monte Carlo (QMC) CASINO-code. The QMC code employed the VMC and DMC methods in the computations with emphasis on DMC, and using Slater-Jastrow trial wave-function formed from Hartree-Fock orbitals. The calculated results show that our reported values are in good agreement with the experimental values of both Hehre et al., and Linus Pauling. The total energies obtained in this study are 6 significant figures more accurate than those of previous studies.

Large scale multi-configuration Hartree-Fock calculation of the hyperfine structure of the ground state of vanadium

Open Physics ◽  
2006 ◽  
Vol 4 (1) ◽  
pp. 42-57
Author(s):  
Oliver Scharf ◽  
Gediminas Gaigalas
Keyword(s):  
Hyperfine Structure ◽  
Ground State ◽  
Large Scale ◽  
Electric Quadrupole ◽  
State Function ◽  
Hartree Fock ◽  
The Core ◽  
Experimental Values ◽  
State Functions ◽  
Good Agreement

AbstractThe hyperfine structure of the ground state of vanadium, 51VI, is calculated in the nonrelativistic framework of the multi-configuration Hartree-Fock approximation. A configuration state function limiting algorithm is used to make the calculations feasible and to study the influence of core, valence and core-valence correlations in detail. The obtained configuration state function space captures the most important orbital correlations within 2%. Further correlations are included through configuration interaction calculation. The atomic state functions are used to evaluate the magnetic dipole hyperfine factor A and the electric quadrupole factor B. It turns out that the ab initio calculation can not capture the core polarization of the 2s shell. It introduces an error that is higher than the Hartree-Fock approximation. However, the detailed correlations being observed suggest the introduction of a wrong correlation orbital due to the algorithm being used. Neglecting this orbital leads to good agreement with 2% deviation from the experimental values for the A factors.

scholarly journals Multiconfiguration Dirac-Hartree-Fock calculations of Landé g-factors for ions of astrophysical interest: B II, C I−IV, Al I−II, Si I−IV, P II, S II, Cl III, Ar IV, Ca I, Ti II, Zr III, and Sn II

2020 ◽  
Vol 639 ◽  
pp. A25 ◽  
Author(s):  
W. Li ◽  
P. Rynkun ◽  
L. Radžiūtė ◽  
G. Gaigalas ◽  
B. Atalay ◽  
...  
Keyword(s):  
General Purpose ◽  
Wave Functions ◽  
Excitation Energies ◽  
Hartree Fock ◽  
Relativistic Configuration ◽  
Experimental Values ◽  
Relativistic Configuration Interaction ◽  
Relative Differences ◽  
Average Uncertainty ◽  
Good Agreement

Aims. The Landé g-factor is an important parameter in astrophysical spectropolarimetry, used to characterize the response of a line to a given value of the magnetic field. The purpose of this paper is to present accurate Landé g-factors for states in B II, C I−IV, Al I−II, Si I−IV, P II, S II, Cl III, Ar IV, Ca I, Ti II, Zr III, and Sn II. Methods. The multiconfiguration Dirac-Hartree-Fock and relativistic configuration interaction methods, which are implemented in the general-purpose relativistic atomic structure package GRASP2K, are employed in the present work to compute the Landé g-factors for states in B II, C I−IV, Al I−II, Si I−IV, P II, S II, Cl III, Ar IV, Ca I, Ti II, Zr III, and Sn II. The accuracy of the wave functions for the states, and thus the accuracy of the resulting Landé g-factors, is evaluated by comparing the computed excitation energies and energy separations with the National Institute of Standards and Technology (NIST) recommended data. Results. All excitation energies are in very good agreement with the NIST values except for Ti II, which has an average difference of 1.06%. The average uncertainty of the energy separations is well below 1% except for the even states of Al I; odd states of Si I, Ca I, Ti II, Zr III; and even states of Sn II for which the relative differences range between 1% and 2%. Comparisons of the computed Landé g-factors are made with available NIST data and experimental values. Analysing the LS-composition of the wave functions, we quantify the departures from LS-coupling and summarize the states for which there is a difference of more than 10% between the computed Landé g-factor and the Landé g-factor in pure LS-coupling. Finally, we compare the computed Landé g-factors with values from the Kurucz database.

Density functional theory (DFT) and Hartree–Fock (HF) calculations of potential p–vinylbenzyl chloride-based macroinitiator for atom transfer radical polymerization

2016 ◽  
Vol 94 (3) ◽  
pp. 290-304 ◽  
Author(s):  
Feride Akman
Keyword(s):  
Experimental Data ◽  
Density Functional Theory ◽  
Potential Energy ◽  
Density Functional ◽  
Energy Surface ◽  
Functional Theory ◽  
Hartree Fock ◽  
Experimental Values ◽  
Good Agreement ◽  
Hf Calculations

The spectroscopic properties of poly (styrene–co–p–vinylbenzyl chloride) (poly (St-co-VBC)) were investigated by Fourier transform infrared spectroscopy and 1H nuclear magnetic resonance spectroscopic techniques. The molecular geometry and vibrational frequencies of macroinitiator, poly (St-co-VBC), were calculated by using density functional theory (DFT) and Hartree–Fock (HF) methods with 6–31 G+ (d, p) as a basis set. Calculated theoretical values are shown to be in good agreement with that of experimental values. An excellent harmony between the two data sets was verified. Besides, the experimental data of macroinitiator were compared with experimental data of its corresponding monomers such as St and VBC. The dimer and trimer forms of macroinitiator are used as significant contributions for getting an accurate interpretation of the experimental frequencies of poly (St-co-VBC). The results revealed that the change from St and VBC to poly (St-co-VBC) should be characterized by the disappearance of the CH2=CH bonds of the vinyl group and the appearance of the aliphatic C–H and CH2 bonds. The geometrical parameters, Mulliken atomic charges and frontier molecular orbitals energies were also calculated using the same theoretical methods. The chemical shifts were calculated by using the gauge–including atomic orbital method and all the theoretically predicted values were shown to be in good agreement with experimental values. Molecular orbital properties, molecular electrostatic potential, and the potential energy surface for the atom transfer radical polymerization (ATRP) of the macroinitiator were studied with DFT and HF calculations. The potential energy surface of the ATRP initiator is decided by their electronic effect and steric hindrance effect simultaneously.

Studies of energy levels, hyperfine structure, and transition probabilities for neutral silicon

2016 ◽  
Vol 94 (4) ◽  
pp. 359-364 ◽  
Author(s):  
Miao Wu ◽  
Guojie Bian ◽  
Xiangfu Li ◽  
Min Xu ◽  
Quanping Fan ◽  
...  
Keyword(s):  
Hyperfine Structure ◽  
Quantum Electrodynamics ◽  
Transition Probabilities ◽  
Theoretical Calculations ◽  
Energy Levels ◽  
Structure Constant ◽  
Hartree Fock ◽  
Hyperfine Structure Constant ◽  
Experimental Values ◽  
Good Agreement

The multi-configuration Dirac–Hartree–Fock method and active space approach are used to investigate the energy levels, hyperfine structure constants, and transition probabilities of a neutral silicon atom. The contributions of Breit interactions and quantum electrodynamics correction are considered. Compared with other theoretical and experimental values of energy levels, our values are in good agreement; the discrepancies of the majority of energy levels calculated are within 1% of experimental values, and the energy levels calculated are very close to other theoretical values. The number of energy levels we considered is larger than that of any other theoretical calculations. The values of the hyperfine structure constant A of the radioactive 29Si atom that we calculated are in good agreement with experimental values. From these results we can predict the hyperfine structure constant A of other states of 29Si where no other theoretical results are available. The transition probabilities of neutral silicon have also been calculated and discussed.

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