Ground-State Properties of Nucleic Acid Constituents Studied by Density Functional Calculations. 3. Role of Sugar Puckering and Base Orientation on the Energetics and Geometry of 2‘-Deoxyribonucleosides and Ribonucleosides

2000 ◽  
Vol 104 (18) ◽  
pp. 4560-4568 ◽  
Author(s):  
Alexandre Hocquet ◽  
Nicolas Leulliot ◽  
Mahmoud Ghomi
Keyword(s):  
Nucleic Acid ◽  
Ground State ◽  
Density Functional Calculations ◽  
Density Functional ◽  
Ground State Properties ◽  
Sugar Puckering ◽  
Base Orientation

scholarly journals f-Electron and Magnetic Ordering Effects in Nickelates LaNiO2 and NdNiO2: Remarkable Role of The Cuprate-Like 3dx2-y2 Band

2020 ◽  
Author(s):  
Jianwei Sun ◽  
Ruiqi Zhang ◽  
Christopher Lane ◽  
Bahadur Singh ◽  
Johannes Nokelainen ◽  
...  
Keyword(s):  
Ground State ◽  
Exchange Coupling ◽  
Density Functional ◽  
High Temperature Superconductivity ◽  
Parent Compound ◽  
Magnetic Ordering ◽  
Striking Similarity ◽  
Infinite Layer ◽  
Open Questions

Abstract Recent discovery of superconductivity in the doped infinite-layer nickelates has renewed interest in understanding the nature of high-temperature superconductivity more generally. The low-energy electronic structure of the parent compound NdNiO2, the role of electronic correlations in driving superconductivity, and the possible relationship betweeen the cuprates and the nickelates are still open questions. Here, by comparing LaNiO2 and NdNiO2 systematically within a parameter free density functional framework, all-electron first-principles framework, we reveal the role Nd 4f-electrons in shaping the ground state of pristine NdNiO2. Strong similarities are found between the electronic structures of LaNiO2 and NdNiO2, except for the effects of the 4f-electrons. Hybridization between the Nd 4f and Ni 3d orbitals is shown to significantly modify the Fermi surfaces of various magnetic states. In contrast, the competition between the magnetically ordered phases depends mainly on the gaps in the Ni dx2-y2 band, so that the ground state in LaNiO2 and NdNiO2 turns out to be striking similarity to that of the cuprates. The d - p band-splitting is found to be much larger while the intralayer 3d ion-exchange coupling is smaller in the nickelates compared to the cuprates. Our estimated value of the on-site Hubbard U is similar to that in the cuprates, but the value of the Hund's coupling JH is found to be sensitive to the Nd magnetic moment. The exchange coupling J in NdNiO2 is only half as large as in the curpates, which may explain why Tc in the nickelates is half as large as the cuprates.

scholarly journals Ground state properties and shape evolution in Pt isotopes within the covariant density functional theory

2019 ◽  
Vol 28 (10) ◽  
pp. 1950078
Author(s):  
Y. El Bassem ◽  
M. Oulne
Keyword(s):  
Density Functional Theory ◽  
Ground State ◽  
Density Functional ◽  
Meson Exchange ◽  
Isotopic Chain ◽  
Functional Theory ◽  
Density Dependent ◽  
Covariant Density Functional Theory ◽  
Ground State Properties ◽  
Covariant Density

In this work, the ground state properties of the platinum isotopic chain, [Formula: see text]Pt are studied within the covariant density functional theory. The calculations are carried out for a large number of even–even Pt isotopes by using the density-dependent point-coupling and the density-dependent meson-exchange effective interactions. All ground state properties such as the binding energy, separation energy, two-neutron shell gap, root mean square (rms)-radii for neutrons and protons and quadrupole deformation are discussed and compared with available experimental data, and with the predictions of some nuclear models such as the Relativistic Mean Field (RMF) model with NL3 functional and the Hartree–Fock–Bogoliubov (HFB) method with SLy4 Skyrme force. The shape phase transition for Pt isotopic chain is also studied. Its corresponding total energy curves as well as the potential energy surfaces confirm the transition from prolate to oblate shapes at [Formula: see text]Pt contrary to some studies predictions and in agreement with others. Overall, a good agreement is found between the calculated and experimental results wherever available.

DINEUTRON CORRELATION IN THE GROUND STATE AND E1 EXCITATIONS OF BORROMEAN NUCLEI

2010 ◽  
Vol 25 (21n23) ◽  
pp. 1842-1845
Author(s):  
K. HAGINO ◽  
H. SAGAWA ◽  
T. OISHI
Keyword(s):  
Contact Interaction ◽  
Ground State ◽  
Energy Distributions ◽  
Weakly Bound ◽  
Density Dependent ◽  
Body Model ◽  
Dipole Excitation ◽  
Ground State Properties ◽  
Three Body

Using a three-body model with density-dependent contact interaction, we discuss the role of dineutron correlation in the ground state properties as well as in the dipole excitation of typical weakly-bound Borromean nuclei, 11 Li and 6 He . We show that, while both the nuclei manifest themselves similar strong dineutron correlations to each other in the ground state, the energy distributions for the two emitted neutrons from the dipole excitation are considerably different. We also discuss briefly the diproton correlation in a proton-rich Borromean nucleus, 17 Ne .

Sign in / Sign up

Export Citation Format

Share Document