A nuclear phenomenological study of the even–even Thorium Isotopes 228–232Th

2018 ◽  
Vol 27 (05) ◽  
pp. 1850040 ◽  
Author(s):  
S. B. Doma ◽  
H. S. El-Gendy
Keyword(s):  
Potential Energy Surfaces ◽  
Phenomenological Study ◽  
Transition Probability ◽  
Phenomenological Approach ◽  
Vibrational Energies ◽  
Boson Model ◽  
Electric Transition ◽  
Energy Surfaces ◽  
Good Agreement ◽  
Thorium Isotopes

The rotational and vibrational energies and the electric transition probability B [Formula: see text] of the even–even [Formula: see text]Th isotopes are studied empirically in framework of a nuclear phenomenological approach by using the SU(3) dynamical symmetries of the Interacting Boson Model-1 (IBM-1). Furthermore, the potential energy surfaces for these isotopes are plotted as functions of the deformation parameters [Formula: see text] and [Formula: see text]. Moreover, we introduce empirical fit formulas for rotational and vibrational energies, which used to calculate these energies for the thorium isotopes. The obtained results by applying the IBM-1 and the authors’ formulas are in good agreement with the corresponding experimental data for most of the nuclear states.

Structure of the low-lying positive and negative parity states in even–even 144−154Nd isotopes

2019 ◽  
Vol 28 (12) ◽  
pp. 1950107
Author(s):  
Hussein N. Qasim ◽  
Falih H. Al-Khudair
Keyword(s):  
Potential Energy Surfaces ◽  
Transition Probability ◽  
Model Space ◽  
Negative Parity ◽  
Energy Spectra ◽  
Interacting Boson Model ◽  
Nd Isotopes ◽  
Nd Isotope ◽  
Boson Model ◽  
Energy Surfaces

The low-lying positive and negative parity states of even–even [Formula: see text]Nd isotopes are studied using the interacting boson model (IBM). The negative parity states are involved within the IBM model by adding a single angular momentum ([Formula: see text]) boson with intrinsic negative parity [Formula: see text]-boson to [Formula: see text] and [Formula: see text]-bosons model space. For these nuclei, the potential energy surfaces [Formula: see text], transition probability [Formula: see text], [Formula: see text] and [Formula: see text] are calculated. Phase transition from the [Formula: see text] limit to the [Formula: see text] limit is observed in the chain and the critical point has been determined for [Formula: see text]Nd isotope. It is found that the calculated positive and negative parity energy spectra of Nd-isotopes agree well with the experimental data.

Energy Levels and Electromagnetic Transition of 90-94mo Nuclei Using Ibm-1

2020 ◽  
pp. 149-152
Keyword(s):  
Experimental Data ◽  
Transition Probability ◽  
Energy Levels ◽  
Dynamical Symmetry ◽  
Interacting Boson Model ◽  
Excitation Energies ◽  
Electromagnetic Transition ◽  
Boson Model ◽  
Energy States ◽  
Good Agreement

The energy states for the J , b , ɤ bands and electromagnetic transitions B (E2) values for even – even molybdenum 90 – 94 Mo nuclei are calculated in the present work of "the interacting boson model (IBM-1)" . The parameters of the equation of IBM-1 Hamiltonian are determined which yield the best excellent suit the experimental energy states . The positive parity of energy states are obtained by using IBS1. for program for even 90 – 94 Mo isotopes with bosons number 5 , 4 and 5 respectively. The" reduced transition probability B(E2)" of these neuclei are calculated and compared with the experimental data . The ratio of the excitation energies of the 41+ to 21+ states ( R4/2) are also calculated . The calculated and experimental (R4/2) values showed that the 90 – 94 Mo nuclei have the vibrational dynamical symmetry U(5). Good agreement was found from comparison between the calculated energy states and electric quadruple probabilities B(E2) transition of the 90–94Mo isotopes with the experimental data .

Vibrational energies for NH3 based on high level ab initio potential energy surfaces

2002 ◽  
Vol 117 (24) ◽  
pp. 11265-11276 ◽  
Author(s):  
Hai Lin ◽  
Walter Thiel ◽  
Sergei N. Yurchenko ◽  
Miguel Carvajal ◽  
Per Jensen
Keyword(s):  
Potential Energy ◽  
Ab Initio ◽  
Potential Energy Surfaces ◽  
Vibrational Energies ◽  
High Level ◽  
Energy Surfaces

scholarly journals On the isotopic fingerprint exerted on carbonyl sulfide by the stratosphere

2012 ◽  
Vol 12 (9) ◽  
pp. 25329-25353 ◽  
Author(s):  
J. A. Schmidt ◽  
S. Hattori ◽  
N. Yoshida ◽  
S. Nanbu ◽  
M. S. Johnson ◽  
...  
Keyword(s):  
Cross Sections ◽  
Potential Energy Surfaces ◽  
Carbonyl Sulfide ◽  
Isotopic Fractionation ◽  
Data Sets ◽  
Mechanical Formalism ◽  
Model Study ◽  
Quantum Mechanical Formalism ◽  
Energy Surfaces ◽  
Good Agreement

Abstract. The isotopic fractionation in OCS photolysis is studied theoretically from first principles. UV absorption cross sections for OCS, OC33S, OC34S, OC36S and O13CS are calculated using the time-depedent quantum mechanical formalism and recent potential energy surfaces for the lowest four singlet and lowest four triplet electronic states. The calculated isotopic fractionations as a function of wavelength are in good agreement with recent measurements by Hattori et al. (2011) and indicate that photolysis leads to only a small enrichment of 34S in the remaining pool of OCS. A simple stratospheric model is constructed taking into account the main stratospheric sink reactions of OCS and it is found that stratospheric removal overall slightly favors light OCS in constrast to the findings of Leung et al. (2002). These results show, based on isotopic considerations, that OCS is an acceptable source of background stratosperic sulfate aerosol in agreement with a recent model study of Brühl et al. (2012). The 13C isotopic fractionation due to photolysis of OCS is significant and will leave a strong signal in the pool of remaining OCS making it a candidate for tracing using the ACE-FTS and MIPAS data sets.

Vibrational energies of H3+ and Li3+ based on the diatomics-in-molecules potentials

1986 ◽  
Vol 51 (10) ◽  
pp. 2057-2062 ◽  
Author(s):  
Jan Vojtík ◽  
Vladimír Špirko ◽  
Per Jensen
Keyword(s):  
Potential Energy ◽  
Ab Initio ◽  
Potential Energy Surfaces ◽  
Vibrational Energy ◽  
Energy Levels ◽  
Vibrational Motion ◽  
Variational Calculations ◽  
Vibrational Energies ◽  
Vibrational Energy Levels ◽  
Energy Surfaces

The present publication reports variational calculations of the vibrational energy levels for H3+, D3+, 6Li3+, and 7Li3+, starting from potential energy surfaces generated by the DIM scheme. The vibrational energies obtained agree semiquantitatively with those based on the best ab initio potentials available. The results seem to indicate that an analogous approach might be useful in describing the vibrational motion of heavier alkali cluster cations A3+.

scholarly journals New H2O–H2O collisional rate coefficients for cometary applications

2020 ◽  
Vol 498 (4) ◽  
pp. 5489-5497 ◽  
Author(s):  
C Boursier ◽  
B Mandal ◽  
D Babikov ◽  
M L Dubernet
Keyword(s):  
Cross Sections ◽  
Potential Energy Surfaces ◽  
Rate Coefficients ◽  
Molecular Systems ◽  
Large Sets ◽  
Alternative Approach ◽  
Collisional Rate Coefficients ◽  
Energy Surfaces ◽  
Good Agreement

ABSTRACT We re-introduce a semiclassical methodology based on theories developed for the determination of broadening coefficients. We show that this simple and extremely fast methodology provides results that are in good agreement with results obtained using the more sophisticate MQCT approach. This semiclassical methodology could be an alternative approach which allows to provide large sets of collisional data for very complex molecular systems. It saves time both on the determination of potential energy surfaces and on the collisional dynamical calculations. In addition, this paper provides more complete sets of rotational de-excitation cross-sections and rate coefficients of H2O perturbed by a thermal average of water molecules. Those data can be used in the radiative transfer modelling of cometary atmospheres.

Computational and ultraviolet photoelectron spectroscopic evidence that (Z)-2-methyl-1,3-pentadiene prefers twisted s-cis conformers in the gas phase

1992 ◽  
Vol 70 (7) ◽  
pp. 1971-1977 ◽  
Author(s):  
Nick Henry Werstiuk ◽  
George Timmins ◽  
Jiangong Ma ◽  
Timothy A. Wildman
Keyword(s):  
Potential Energy ◽  
Gas Phase ◽  
Computational Methods ◽  
Potential Energy Surfaces ◽  
Spectroscopic Evidence ◽  
Orbital Energies ◽  
Trans Conformer ◽  
Energy Surfaces ◽  
Good Agreement

A redetermination of the ultraviolet photoelectron (pe) spectrum of (Z)-2-methyl-1,3-pentadiene has led to a correction of the published spectrum. By studying (Z)-2-methyl-1,3,-pentadiene (1a) and (E)-2-methyl-1,3-pentadiene (1b) with MMX, MNDO, AM1, and abinitio MO computational methods and pe spectroscopy, we have shown that a combination of these methods provides useful insights on the conformational behaviour of methyl-substituted 1,3-dienes in the gas phase. Synthetic pe spectra, derived from the computed potential energy surfaces and angle-dependent orbital energies, are in good agreement with experiment. Thus, the E isomer prefers the s-trans conformer but the Z isomer prefers twisted s-cis conformations in the gas phase.

scholarly journals Description of the energy levels and electric quadrupole transitions of the 92Nb and 92Mo nuclei using nuclear shell model

2021 ◽  
Author(s):  
Mustafa Mohammed Jabbar ◽  
Keyword(s):  
Transition Probabilities ◽  
Transition Probability ◽  
Energy Levels ◽  
Electric Quadrupole ◽  
Electric Quadrupole Transition ◽  
Modified Surface ◽  
Electric Transition ◽  
Experimental Values ◽  
Nuclear Shell ◽  
Good Agreement

In current study ,92Nb and 92Mo isotopes have been determined for calculating energy levels and electric quadrupole transition probabilities. Two interaction have been applied in this study are surface delta and modified surface delta interactions. The calculations have been achieved by using appropriate effective charges for proton and neutron as well as parameter length of harmonic potential. Computed results have been compared with the experimental values. After this comparison, energy and the transition probability values have a good agreement with the experimental values, also there are values of the total angular momentum and parity are determined and confirmed for some of the experimental energies, undetermined and unconfirmed experimentally. Theoretically, new values of quadrupole electric transition probabilities have been explored which have not been known in the experimental data.

Modélisation classique de champs de forces d’interactions additives dans les agrégats de type X+ Arn, (X = Li et K); mécanisme de croissance

2008 ◽  
Vol 86 (7) ◽  
pp. 911-918 ◽  
Author(s):  
F Ben Salem ◽  
F Taarit ◽  
M Ben El Hadj Rhouma ◽  
Z Ben Lakhdar
Keyword(s):  
Monte Carlo ◽  
Mass Spectrum ◽  
Potential Energy ◽  
Relative Stability ◽  
Potential Energy Surfaces ◽  
Point Of View ◽  
Magic Numbers ◽  
Energy Surfaces ◽  
Structural Point ◽  
Good Agreement

The structure and stability of the Li+Arn and K+Arn clusters are studied using pair additive potentials adapted to reproduce the ab initio calculations that we estimate as the most accurate for the Li+Ar, K+Ar, and Ar–Ar dimers. The exploration of the potential energy surfaces of the Li+Arn and K+Arn systems was carried out with Wales’ method, which includes Monte-Carlo and deformation methods. From a structural point of view, one identifies a construction mechanism in very good agreement with the interpretation of the mass spectrum done by Velegrakis, including a difference for the n = 10 case. The study of the relative stability of these structures yields magic numbers for n = 8, 10, 14, 16, 18, 20, 22, 30, 32, and 34, which are in good agreement with the experiment. [Journal translation]

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