Inclusive quasielastic neutrino-nucleus scattering with energy density functional nuclear models

In this study,we calculated the inclusive charged-current neutrino-nucleus scattering from ^(40)Ar in the quasielastic region.To explore the effect of uncertainties stemming from the nuclear structure,we used the KIDS(Korea-IBS-Daegu-SKKU)nuclear energy density functional and Skyrme force models,namely SLy4,SkI3,and MSk7.These models were selected to have distinct behavior in terms of the density dependence of the symmetry energy and the effective mass of the nucleon.In the charged-current neutrino scattering,the single-and double-differential cross sections were calculated for various kinematics.Total cross sections are reported as a function of the incident neutrino energy.The theoretical cross sections were compared with experimental data,and the roles of the effective mass and symmetry energy were investigated in terms of charged-current neutrino-nucleus scattering.

New quantification of symmetry energy from neutron skin thicknesses of^(48)Ca and^(208)Pb

Precise knowledge of the nuclear symmetry energy can be tentatively calibrated using multimessenger constraints.The neutron skin thickness of a heavy nucleus is one of the most sensitive indicators for probing the isovector components of effective interactions in asymmetric nuclear matter.Recent studies have suggested that the experimental data from the CREX and PREX2 collaborations are not mutually compatible with existing nuclear models.In this study,we review the quantification of the slope parameter of the symmetry energy L from the neutron skin thicknesses of^(48)Ca and^(208)Pb.Skyrme energy density functionals classified by various isoscalar incompressibility coefficients K were employed to evaluate the bulk properties of finite nuclei.The calculated results suggest that the slope parameter L deduced from^(208)Pb is sensitive to the compression modulus of symmetric nuclear matter,but not that from^(48)Ca.The effective parameter sets classified by K=220 MeV can provide an almost overlapping range of L from^(48)Ca and^(208)Pb.

Microscopic analysis of octupole shape transitions in neutron-rich actinides with relativistic energy density functional

Quadrupole and octupole deformation energy surfaces, low-energy excitation spectra, and electric transition rates in eight neutron-rich isotopic chains – Ra, Th, U, Pu, Cm, Cf, Fm, and No – are systematically analyzed using a quadrupole-octupole collective Hamiltonian model, with parameters determined by constrained reflectionasymmetric and axially-symmetric relativistic mean-field calculations based on the PC-PK1 energy density functional.The theoretical results of low-lying negative-parity bands, odd-even staggering, average octupole deformations β3,and B（E3;31- →01＋） show evidence of a shape transition from nearly spherical to stable octupole-deformed, and finally octupole-soft equilibrium shapes in the neutron-rich actinides. A microscopic mechanism for the onset of stable octupole deformation is also discussed in terms of the evolution of single-nucleon orbitals with deformation.

Fully self-consistent calculation ofβ-decay half-lives within Skyrme energy density functional

β-decay half-lives of some magic and semi-magic nuclei have been studied in a fully self-consistent Skyrme Hartree-Fock(HF) plus charge-exchange random phase approximation(RPA).The self-consistency is addressed,in that the same Skyrme energy density functional is adopted in the calculation of ground states and Gamow-Teller excited states.First,the impact of J2 terms on the β-decay half-lives is investigated by using the SGII interaction,revealing a large influence.Subsequently,numerical calculations are performed for the selected nuclei with Skyrme energy density functionals SGII,LNS,SKX,and SAMi.Finally,comparisons to available experimental data and predictions of different theoretical models are discussed.

Theoretical Calculation about the High Energy Density Molecules of Nitrate Ester Substitution Derivatives of Prismane

The nitrate ester substitution derivatives of prismane were studied at the B3LYP/6-311G＊＊ level. The sublimation enthalpies and heats of formation in gas phase and solid state were calculated. The detonation performances were also predicted by using the famous Kamlet-Jacbos equation. Our calculated results show that introducing nitrate ester group into prismane is helpful to enhance its detonation properties. Stabilities were evaluated through the bond dissociation energies, bond order, characteristic heights（H50） and band gap calculations. The trigger bonds in the pyrolysis process of prismane derivatives were confirmed as O–ON2 bond. The BDEs of all compounds were large, so these prismane derivatives have excellent stability consistent with the results of H50 and band gap.

Theoretical Study on the C-H Activation in Decarbonylation of Acetaldehyde by NiL_2(L=SO_3CH_3) Using Density Functional Theory

Density functional theory calculations were carried out to explore the potential energy surface（PES） associated with the gas-phase reaction of Ni L2（L=SO3CH3） with acetone. The geometries and energies of the reactants, intermediates, products and transition states of the triplet ground potential energy surfaces of [Ni, O, C2, H4] were obtained at the B3LYP/6-311＋＋G（d,p） levels in C,H,O atoms and B3LYP/ Lanl2 dz in Ni atom. It was found through our calculations that the decabonylation of acetaldehyde contains four steps including encounter complexation, C-C activation, aldehyde H-shift and nonreactive dissociation. The results revealed that C-C activation induced by Ni L2（L=SO3CH3） led to the decarbonylation of acetaldehyde.

Potential energy surface and formation of superheavy nuclei with the Skyrme energy-density functional

With the Skyrme energy-density functional theory,the nucleus–nucleus potential is calculated and the potential energy surface is obtained with different effective forces for accurately estimating the formation cross sections of superheavy nuclei in massive fusion reactions.The width and height of the potential pocket are influenced by the Skyrme effective forces SkM,SkM^(*),SkP,SIII,Ska,and SLy4,which correspond to the different equations of state for the isospin symmetry nuclear matter.It is found that the nucleus–nucleus potential is associated with the collision orientation and Skyrme forces.A more repulsive nuclear potential is pronounced with increasing the incompressible modulus of nuclear matter,which hinders the formation of superheavy nuclei.The available data in the fusion-evaporation reaction of ^(48)Ca+^(238)U are nicely reproduced with the SkM^(*) parameter by implementing the potential into the dinuclear system model.

The First Principles Study of Li, Al and Ca Doped Zigzag(7,0) Single Walled Carbon Nanotube

We use the ab initio density functional theory to calculate the band structure, density of states, charge transfer, charge density difference, binding energy and vibration frequency. We can see that the conduction band through the Fermi level include SWNT/H_2/Li, SWNT/H_2/Al and SWNT/H_2/Ca, which shows a kind of metallic character. The charge distribution and contour plots of charge difference density of ion/H_2/SWNT show charge transfer between ion and H_2 molecules rather than between H_2 and H_2. Meanwhile, the interaction between Al, Ca and H_2 is weaker than that of Li. We can also prove that the ion is the primary reason to the increase of adsorption energy of hydrogen molecule in SWNT. Finally, we calculate the vibration frequency and don＇t find any imaginary frequency, which proves that the（7,0） SWNT is more stable.

Shape evolution of 72,74Kr with temperature in covariant density functional theory

The rich phenomena of deformations in neutron-deficient krypton isotopes, such as shape evolution with neutron number and shape coexistence, have attracted the interest of nuclear physicists for decades. It is interesting to study such shape phenomena using a novel way, e.g. by thermally exciting the nucleus. In this work, we develop the finite temperature covariant density functional theory for axially deformed nuclei with the treatment of pairing correlations by the BCS approach, and apply this approach for the study of shape evolution in 72,74Kr with increasing temperature. For 72Kr, with temperature increasing, the nucleus firstly experiences a relatively quick weakening in oblate deformation at temperature T-0.9 MeV, and then changes from oblate to spherical at T-2.1 MeV. For 74Kr, its global minimum is at quadrupole deformation β2--0.14 and abruptly changes to spherical at T-1.7 MeV. The proton pairing transition occurs at critical temperature 0.6 MeV following the rule Tc =0.6△p （0）, where △p（0） is the proton pairing gap at zero temperature. The signatures of the above pairing transition and shape changes can be found in the specific heat curve. The single-particle level evolutions with temperature are presented.

Shell corrections with finite temperature covariant density functional theory

The temperature dependence of the shell corrections to the energy sEsell,entropy T8S sell,and free en-ergy oFshell is studied by employing the covariant density functional theory for closed-shell nuclei.Taking 144Sm as an example,studies have shown that,unlike the widely-used exponential dependence exp(-E*/Ed),8Eshell exhibits a non-monotonous behavior,ie.,first decreasing 20%approaching a temperature of 0.8 MeV,and then fading away exponentially.Shell corrections to both free energy 8F shell and entropy T8S shell can be approximated well using the Bohr-Mottelson forms T/sinh(t)and[rcoth(r)-1]/sinh(r),respectively,in which Tx T.Further studies on the shell corrections in other closed-shell nuclei,100Sn and 208 Pb,are conducted,and the same temperature dependen-cics are obtained.

Curvature and Size Effects on Reactivities of Mono-to Octa-vacancies in a(5,5) Single-walled Carbon Nanotube

Defect curvature was developed based on our previously proposed direction curvature theory. Defect curvature, as a universal criterion, was used to identify vacancy formation energies E_f of mono-vacancies to octa-vacancies in a（5,5） tube. An ab initio calculation results showed that E_f decreased with increasing the defect curvature K_（V_s）（s = 1~8）. The structures with removed carbon atoms along zigzag chain or the tubular axis were the most stable in each kind of Vs, because their corresponding K_（V_s） was the largest. In addition, local product structures disturbed the variation rule of E_f as K_（V_s）. There was an odd-even oscillation rule in the smallest E_f among each kind of Vs as the s value and vacancies V2, V4 and V6 were more stable. The stabilities of the related vacancy structures were confirmed by two dissociation processes.

Hydrogenation of graphene nanoflakes and C-H bond dissociation of hydrogenated graphene nanoflakes： a density functional theory study

The Gibbs free energy change for the hydro- genation of graphene nanoflakes Cn （n = 24, 28, 30 and 32） and the C-H bond dissociation energy of hydrogenated graphene nanoflakes CnHm （n = 24, 28, 30 and 32; and m = 1, 2 and 3） are evaluated using density functional theory calculations. It is concluded that the graphene nanoflakes and hydrogenated graphene nanoflakes accept the orth- aryne structure with peripheral carbon atoms bonded via the most triple bonds and leaving the least unpaired dan- gling electrons. Five-membered rings are formed at the deep bay sites attributing to the stabilization effect from the pairing of dangling electrons. The hydrogenation reactions which eliminate one unpaired dangling electron and thus decrease the overall multiplicity of the graphene nanoflakes or hydrogenated graphene nanoflakes are spontaneous with negative or near zero Gibbs free energy change. And the resulting C-H bonds are stable with bond dissociation energy in the same range as those of aromatic compounds. The other C-H bonds are not as stable attributing to the excessive unpaired dangling electrons being filled into the C-H anti-bond orbital.

Thermodynamic properties of ZnSe under pressure and with variation in temperature

The thermodynamic properties of Zn Se are obtained by using quasi-harmonic Debye model embedded in Gibbscode for pressure range 0–10 GPa and for temperature range 0–1000 K. Helmholtz free energy, internal energy, entropy,Debye temperature, and specific heat are calculated. The thermal expansion coefficient along with Gruneisen parameter are also calculated at room temperature for the pressure range. It is found that internal energy is pressure dependent at low temperature, whereas entropy and Helmholtz free energy are pressure sensitive at high temperature. At ambient conditions,the obtained results are found to be in close agreement to available theoretical and experimental data.

Investigation of pyrite surface state by DFT and AFM

The surface states of pyrite(Fe S2) were theoretically investigated using first principle calculation based on the density functional theory(DFT). The results indicate that both the(200) and(311) surfaces of pyrite undergo significant surface atom relaxation after geometry optimization, which results in a considerable distortion of the surface region. In the normal direction, i.e., perpendicular to the surface, S atoms in the first surface layer move outward from the bulk, while Fe atoms move toward the bulk, forming an S-rich surface. The surface relaxation processes are driven by electrostatic interaction, which is evidenced by a relative decrease in the surface energy after surface relaxation. Such a relaxation process is visually interpreted through the qualitative analysis of molecular mechanics. Atomic force microscopy(AFM) analysis reveals that only sulfur atom is visible on the pyrite surface. This result is consistent with the DFT data. Such S-rich surface has important influence on the flotation properties of pyrite.

Global analysis of Skyrme forces with higher-order density dependencies

The density-dependent term in Skyrme forces is essential to simulate three-body and many-body correlations beyond the low-momentum two-body interaction. We speculate that a single density term may be insumcient and a higher-order density dependent term is added. The present work investigates the influence of higher-order density dependencies based on extended UNEDF0 and SkM＊ forces. Global descriptions of nuclear masses and charge radii are presented. The extended UNEDF0 force gives a global rms error on binding energies of 1.29 MeV. The influence on fission barriers and equation of state are also investigated. Perspectives to improve Skyrme forces are discussed, including global center-of-mass corrections and Lipkin-Nogami pairing corrections.

Driving potential and fission-fragment charge distributions

We propose an efficient approach to describe the fission-fragment charge yields for actinides based on the driving potential of the fissioning system.Considering the properties of primary fission fragments at their ground states,the driving potential,which represents the potential energies of the system around scission configuration and closely relates to the yields of fragments,can be unambiguously and quickly obtained from the Skyrme energy-density functional together with the Weizs?cker-Skyrme mass model.The fission-fragment charge distributions for thermal-neutron-induced fission and spontaneous fission of a series of actinides,especially the odd-even staggering in the charge distributions,can be well reproduced.Nuclear dynamical deformations and pairing corrections of fragments play an important role in the charge distributions.

Isospin dependent properties of the isotopic chains of Scandium and Titanium nuclei within the relativistic mean-field formalism

Density-dependent nuclear symmetry energy is directly related to iso spin asymmetry for finite and infinite nuclear systems.It is critical to determine the coefficients of symmetry energy and their related observables because they hold great importance in different areas of nuclear physics,such as the analysis of the structure of ground state exotic nuclei and neutron star studies.The ground state bulk properties of Scandium(Z=21) and Titanium(Z=22) nuclei are calculated,such as their nuclear binding energy(B.E.),quadrupole deformation(β_2),two-neutron separation energy(S_(2 n)),differential variation in the two-neutron separation energy(dS_(2 n)),and root-mean-square charge radius(r_(ch)).The iso spin properties,namely the coefficient of nuclear symmetry energy and its components,such as the surface and volume symmetry energy of a finite isotopic chain,from the corresponding quantities of infinite nuclear matter,are also estimated.Finally,we correlate the neutron-skin thickness with the coefficient of symmetry energy and the related observables corresponding to the isotopic chains of these nuclei.The coherent density fluctuation model(CDFM) is used to estimate the iso spin-dependent properties of finite nuclei,such as symmetry energy,surface symmetry energy,and volume symmetry energy,from their corresponding component in infinite nuclear matter.The relativistic mean-field(RMF) formalism with non-linear NL3 and relativistic-Hartree-Bogoliubov theory with density-dependent DD-ME2 interaction parameters are employed in the analysis.The weight function |F(x)|^(2) is estimated using the total density of each nucleus,which in turn is used with the nuclear matter quantities to obtain the effective symmetry energy and its components in finite nuclei.We calculate the ground state bulk properties,such as nuclear binding energy,quadrupole deformation,two-neutron separation energy,differential variation in the two-neutron separation energy,and root-mean-square charge radius,for the Sc-and Ti-isotopic chains using the non-linear NL 3 and density-dependent DD-ME2 parameter sets.Furthermore,the ground state density distributions are used within the CDFM to obtain the effective surface properties,such as symmetry energy and its components,namely volume and surface symmetry energy,for both the parameter sets.The calculated quantities are used to understand the isospin dependent structural properties of finite nuclei near and beyond the drip line,which broadens the scope of discovering new magicity along the isotopic chains.A shape transition is observed from spherical to prolate near N≥44 and N≥40 for the Sc-and Ti-isotopic chains,respectively.Notable signatures of shell and/or sub-shell closures are found for the magic neutron numbers N=20 and 28 for both isotopic chains using the nuclear bulk and isospin quantities.In addition to these,a few shell/sub-shell closure signatures are observed near the drip-line region at N=34 and 50 by following the surface/isospin dependent observables,namely symmetry energy and its component,for both the isotopic chain of odd-A Sc-and even-even Ti-nuclei.

Isovector giant dipole resonances in proton-rich Ar and Ca isotopes

The isovector giant dipole resonances(IVGDR)in proton-rich Ar and Ca isotopes have been systematic-ally investigated using the resonant continuum Hartree-F ock+BCS(HF+BCS)and quasiparticle random phase ap-proximation(QRPA)methods.The Skyrme SLy5 and density-dependent contact pairing interactions are employed in the calculations.In addition to the giant dipole resonances at energy around 18 MeV,pygmy dipole resonances(PDR)are found to be located in the energy region below 12 MeV.The calculated energy-weighted moments of PDR in nuclei close to the proton drip-line exhaust about 4%of the TRK sum rule.The strengths decrease with in-creasing mass number in each isotopic chain.The transition densities of the PDR states show that motions of pro-tons and neutrons are in phase in the interiors of nuclei,while the protons give the main contribution at the surface.By analyzing the QRPA amplitudes of proton and neutron 2-quasiparticle configurations for a given low-lying state,we find that only a few proton configurations give significant contributions.They contribute about 95%to the total QRPA amplitudes,which indicates that the collectivity of PDR states is not strong in proton-rich nuclei in the present study.