Modelling of the total excitation energy partition including fragment deformation and excitation energies at scission

2012 ◽  
Vol 39 (5) ◽  
pp. 055103 ◽  
Author(s):  
C Morariu ◽  
A Tudora ◽  
F-J Hambsch ◽  
S Oberstedt ◽  
C Manailescu
Keyword(s):  
Excitation Energy ◽  
Energy Partition ◽  
Excitation Energies ◽  
Total Excitation Energy

ENERGY PARTITION IN 235U FISSION REACTION INDUCED BY THERMAL NEUTRON

2012 ◽  
Vol 21 (08) ◽  
pp. 1250073 ◽  
Author(s):  
YONG-JING CHEN ◽  
JING QIAN ◽  
TING-JIN LIU ◽  
ZHU-XIA LI ◽  
XI-ZHEN WU ◽  
...  
Keyword(s):  
Excitation Energy ◽  
Heavy Fragment ◽  
Incident Neutron ◽  
Shell Effect ◽  
Incident Neutron Energy ◽  
Energy Partition ◽  
Fission Reaction ◽  
Fission Fragments ◽  
Total Excitation Energy ◽  
235U Fission

The partition of the total excitation energy between the fission fragments for the n th +235 U and n(En = 5.55 MeV)+235 U fission reactions are analyzed with the experimental data available. Our results show that the total excitation energy is not shared by the fragments in proportion of their masses but support the so-called energy sorting-mechanism. The temperature of the heavy fragment is generally lower than that of the light one when the shell effect does not play a strong role. As soon as the mass of heavy fragment closes to 132, its temperature becomes higher than the complementary light one because of strong shell effect. Our results also show that the heavy fragments gain more energy than the complementary light ones when the incident neutron energy increases.

Possible reference method of total excitation energy partition between complementary fission fragments

2011 ◽  
Vol 867 (1) ◽  
pp. 12-40 ◽  
Author(s):  
C. Manailescu ◽  
A. Tudora ◽  
F.-J. Hambsch ◽  
C. Morariu ◽  
S. Oberstedt
Keyword(s):  
Excitation Energy ◽  
Reference Method ◽  
Energy Partition ◽  
Fission Fragments ◽  
Total Excitation Energy

Modification of HAM/3 excitation energies for ΠΠ* transitions of linear molecules

1980 ◽  
Vol 58 (16) ◽  
pp. 1687-1690 ◽  
Author(s):  
Delano P. Chong
Keyword(s):  
Excitation Energy ◽  
Explicit Expression ◽  
Excited States ◽  
Configuration Interaction ◽  
Excitation Energies ◽  
Carbon Suboxide ◽  
Numerical Examples ◽  
Energy Correction ◽  
Linear Molecules ◽  
Configuration Interaction Calculations

The excitation energies calculated by the HAM/3 procedure for ΠΠ* transitions in linear molecules can be internally inconsistent by as much as ± 0.6 eV. In the recent study by Åsbrink etal., the problem was avoided by adopting Recknagel's expressions and requiring the proper average ΠΠ* excitation energy. In this paper, we trace the small inconsistency back to its origin in HAM/3 theory and derive the analytical expression for the energy correction as well as Recknagel's formulas. Numerical examples studied include all seven linear molecules investigated by Åsbrink etal. The explicit expression for the correction enables us to perform meaningful configuration-interaction calculations on the excited states, as illustrated by the carbon suboxide molecule.

scholarly journals Predicting the UV–vis spectra of oxazine dyes

2011 ◽  
Vol 7 ◽  
pp. 432-441 ◽  
Author(s):  
Scott Fleming ◽  
Andrew Mills ◽  
Tell Tuttle
Keyword(s):  
Excitation Energy ◽  
Density Functional ◽  
Polarizable Continuum Model ◽  
Implicit Solvent ◽  
Continuum Approach ◽  
Excitation Energies ◽  
Functional Theory ◽  
Partial Charges ◽  
Td Dft ◽  
Polarizable Continuum

In the current work we have investigated the ability of time-dependent density functional theory (TD-DFT) to predict the absorption spectra of a series of oxazine dyes and the effect of solvent on the accuracy of these predictions. Based on the results of this study, it is clear that for the series of oxazine dyes an accurate prediction of the excitation energy requires the inclusion of solvent. Implicit solvent included via a polarizable continuum approach was found to be sufficient in reproducing the excitation energies accurately in the majority of cases. Moreover, we found that the SMD solvent model, which is dependent on the full electron density of the solute without partitioning into partial charges, gave more reliable results for our systems relative to the conductor-like polarizable continuum model (CPCM), as implemented in Gaussian 09. In all cases the inclusion of solvent reduces the error in the predicted excitation energy to <0.3 eV and in the majority of cases to <0.1 eV.

scholarly journals A New Benchmark Set for Excitation Energy of Charge Transfer States: Systematic Investigation of Coupled-Cluster Type Methods

2020 ◽  
Author(s):  
Balázs Kozma ◽  
Attila Tajti ◽  
Baptiste Demoulin ◽  
Róbert Izsák ◽  
Marcel Nooijen ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Excitation Energy ◽  
Systematic Investigation ◽  
Coupled Cluster ◽  
Excitation Energies ◽  
Chemical Methods ◽  
Valence States ◽  
Quantum Chemical Methods ◽  
Material Physics ◽  
Cluster Methods

There are numerous publications on benchmarking quantum chemistry methods for excited states. These studies rarely include Charge Transfer (CT) states although many interesting phenomena in e.g. biochemistry and material physics involve transfer of electron between fragments of the system. Therefore, it is timely to test the accuracy of quantum chemical methods for CT states, as well. In this study we first suggest a set benchmark systems consisting of dimers having low-energy CT states. On this set, the excitation energy has been calculated with coupled cluster methods including triple excitations (CC3, CCSDT-3, CCSD(T)(a)* ), as well as with methods including full or approximate doubles (CCSD, STEOM-CCSD, CC2, ADC(2), EOM-CCSD(2)). The results show that the popular CC2 and ADC(2) methods are much more inaccurate for CT states than for valence states. On the other hand, CCSD seems to have similar systematic overestimation of the excitation energies for both valence and CT states. Concerning triples methods, the new CCSD(T)(a)* method including non-iterative triple excitations preforms very well for all type of states, delivering essentially CCSDT quality results.<br>

SHAPE EVOLUTION OF 96ZR AND 96MО WITH EXCITATION ENERGY INCREASE

2019 ◽  
pp. 37-41
Author(s):  
M.A. Mardyban ◽  
D.A. Sazonov ◽  
E.A. Kolganova ◽  
R.V. Jolos
Keyword(s):  
Potential Energy ◽  
Excitation Energy ◽  
Transition Probabilities ◽  
Collective Excitations ◽  
Nuclear Model ◽  
Shape Evolution ◽  
Energy Increase ◽  
Excitation Energies ◽  
Satisfactory Description

The observed properties of the low-lying collective excitations of 96Zr and 96Mo are investigated in the framework of the collective quadrupole nuclear model with the Bohr Hamiltonian, whose potential energy has two minima – spherical and deformed. Satisfactory description of the excitation energies and E2 transition probabilities is obtained. It is shown that in the case of 96Zr both minima are sufficiently deep. However, in the case of 96Mo a deformed minimum is only outlined.

scholarly journals Spin?Parity Combinations in 32S

1973 ◽  
Vol 26 (6) ◽  
pp. 747 ◽  
Author(s):  
PR Gardner ◽  
DC Kean ◽  
RH Spear ◽  
AM Baxter ◽  
RAI Bell ◽  
...  
Keyword(s):  
Solid State ◽  
Excitation Energy ◽  
Negative Parity ◽  
Excitation Energies ◽  
Spin Parity ◽  
Magnetic Analysis ◽  
Parity Level ◽  
Natural Parity

Inelastically scattered IX-particles from the reaction 32S(IX, 1X')32S have been studied with solid state counters at extreme backward angles in order to determine spin-parity combinations for levels in 32S at excitation energies Ex up to 7 �15 MeV. The results confirm the well-established spin and parity values, show that the 5� 798 MeV spin 1 state has negative parity, and provide narrow limits for the possible spin and parity values of the 6'410,6' 666,6' 762, and 6� 854 MeV levels. A previously unreported natural parity level was found at Ex = 6�58 MeV. Magnetic analysis of the reaction 32S(p, p')32S confirmed the existence of this level and established its excitation energy as 6�581�0�003 MeV. Particle-y-ray coincidence studies showed that this level decays predominantly by y-ray transitions to the 2�23 MeV 2 + state.

The limiting total excitation energy of the nucleus and Levinson's theorem

1988 ◽  
Vol 14 (4) ◽  
pp. L61-L65
Author(s):  
F A Almeida ◽  
Y T Chen ◽  
M S Hussein ◽  
R Donangelo
Keyword(s):  
Excitation Energy ◽  
Levinson’S Theorem ◽  
Total Excitation Energy

scholarly journals Partition of electronic excitation energies: the IQA/EOM-CCSD method

2019 ◽  
Vol 21 (25) ◽  
pp. 13428-13439 ◽  
Author(s):  
Alberto Fernández-Alarcón ◽  
José Luis Casals-Sainz ◽  
José Manuel Guevara-Vela ◽  
Aurora Costales ◽  
Evelio Francisco ◽  
...  
Keyword(s):  
Electronic Excitation ◽  
Noncovalent Interactions ◽  
Equation Of Motion ◽  
Electronic Energy ◽  
Molecular Cluster ◽  
Coupled Cluster ◽  
Energy Partition ◽  
Excitation Energies ◽  
Coupled Cluster Theory ◽  
Interacting Quantum Atoms

We put together equation of motion coupled cluster theory and the interacting quantum atoms electronic energy partition to determine how an absorbed photon changes atomic energies as well as covalent and noncovalent interactions within a molecule or molecular cluster.

Narrow-Band Synchrotron Radiation Excitation of Soft X-Ray Emission Spectra

1993 ◽  
Vol 307 ◽  
Author(s):  
K. E. Miyano ◽  
W. L. O'Brien ◽  
D. L. Ederer ◽  
T. A. Callcott ◽  
J. J. Jia ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Excitation Energy ◽  
Crystalline Silicon ◽  
Narrow Band ◽  
Emission Spectra ◽  
Phonon Coupling ◽  
Excitation Energies ◽  
Final State ◽  
X Ray ◽  
The Core

ABSTRACTMonochromatized synchrotron radiation has been employed as the excitation source for soft x-ray emission spectroscopy. In the present paper changes in the emission spectra that occur as the excitation energy is varied near the core-absorption threshold are discussed. In the case of crystalline silicon, strong variations are seen in the L2,3 emission for excitation energies up to 30 eV above threshold. These variations are shown to be dependent on the crystalline order of the material and can be interpreted in terms of restrictions on the crystal momentum that arise in an inelastic scattering description of the combined absorption and emission. On the other hand this description is less relevant to the excitation-energy dependence of ionic insulators, in which strong phonon coupling removes these restrictions on crystal momentum. In the insulators B2O3 and BN strong variations in the emission are observed at threshold, upon creation of a core exciton: the exciton affects the emission through its influence on the phonon coupling as well as on the initial and final-state screening.

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