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The Gauge-Including Projector Augmented Wave (GIPAW) method, within the Density Functional Theory (DFT) Generalized Gradient Approximation (GGA) framework, is applied to compute solid state NMR parameters for $^{27}Al$ in the $\alpha$,…

First-principles density functional theory (DFT) oxygen chemical shift tensors were calculated for A(B,B$^{\prime}$)O$_3$ perovskite alloys Pb(Zr$_{1/2}$Ti$_{1/2}$)O$_3$ (PZT) and Pb(Mg$_{1/3}$Nb$_{2/3}$)O$_3$ (PMN). Quantum chemistry…

材料科学 · 物理学 2015-05-28 Daniel L. Pechkis , Eric J. Walter , Henry Krakauer

Thiolate containing mercury(II) complexes of the general formula [Hg(SR)$_n$]$^{2-n}$ have been of great interest since the toxicity of mercury was recognized. $^{199}$Hg nuclear magnetic resonance spectroscopy (NMR) is a powerful tool for…

化学物理 · 物理学 2024-08-05 Haide Wu , Lars Hemmingsen , Stephan P. A. Sauer

A DFT-based method is presented which allows the computation of all-electron NMR shifts of metallic compounds with periodic boundary conditions. NMR shifts in metals measure two competing physical phenomena. Electrons interact with the…

材料科学 · 物理学 2009-11-13 Mayeul d'Avezac , Nicola Marzari , Francesco Mauri

We report $^{105}$Pd NMR and NQR measurements on a single crystal of Ce$_3$Pd$_{20}$Si$_6$, where antiferroquadrupolar and antiferromagnetic orders develop at low temperature. From the analysis of NQR and NMR spectra, we have determined the…

We report inelastic neutron scattering measurements of crystal field transitions in PrFeAsO, PrFeAsO0.87F0.13, and NdFeAsO0.85F0.15. Doping with fluorine produces additional crystal field excitations, providing evidence that there are two…

Nuclear magnetic resonance (NMR) has been widely used in the graphene oxide (GO) structure study. However, the detailed relationship between its spectroscopic features and the GO structural configuration has remained elusive. Based on first…

材料科学 · 物理学 2015-03-13 Ning Lu , Ying Huang , Haibei Li , Zhenyu Li , Jinlong Yang

A systematic study of the ground-state properties of even-even rare earth nuclei has been performed in the framework of the Relativistic Mean-Field (RMF) theory using the parameter set NL-SH. Nuclear radii, isotope shifts and deformation…

核理论 · 物理学 2009-10-28 G. A. Lalazissis , M. M. Sharma , P. Ring

Nuclear Magnetic Resonance (NMR) chemical shifts are powerful probes of local atomic and electronic structure that can be used to resolve the structures of powdered or amorphous molecular solids. Chemical shift driven structure elucidation…

An indispensable step to understand collective magnetic phenomena in rare-earth compounds is the determination of spatially-anisotropic single-ion properties resulting from spin-orbit coupling and crystal field (CF). The CF Hamiltonian has…

强关联电子 · 物理学 2021-04-07 Zhiling Dun , Xiaojian Bai , Matthew B. Stone , Haidong Zhou , Martin Mourigal

NMR is the technique of election to probe the local properties of materials. Herein we present the results of density functional theory (DFT) \textit{ab initio} calculations of the NMR parameters for fluorapatite (FAp), a calcium…

材料科学 · 物理学 2012-07-27 Barbara Pavan , Davide Ceresoli , Mary M. J. Tecklenburg , Marco Fornari

This review presents a concise, yet comprehensive discussion on the evolution of theoretical methods employed to determine the ground and excited states of molecules in weak and strong magnetic fields. The weak-field cases have been studied…

原子与分子团簇 · 物理学 2021-05-31 Mihir Date , R. W. A Havenith

Due to the complex interactions between rare-earth elements and transition metals, as well as/or themselves, rare-earth transition-metal oxides are likely to exhibit highly intriguing and novel magnetic structures and dynamic behaviours.…

The crystalline electric field (CEF) is investigated in Pr$_3$Pt$_{23}$Si$_{11}$ and Nd$_3$Pt$_{23}$Si$_{11}$ by neutron spectroscopy (NS). At low temperature, the number of observed CEF excitations is consistent with the orthorhombic…

强关联电子 · 物理学 2016-12-13 R. M. Galéra , C. Opagiste , M. Amara , J. C. Toussaint , M. B. Lepetit , S. Rols

We present first-principles, density-functional theory calculations of the NMR chemical shifts for polycyclic aromatic hydrocarbons, starting with benzene and increasing sizes up to the one- and two-dimensional infinite limits of graphene…

材料科学 · 物理学 2009-09-07 T. Thonhauser , D. Ceresoli , N. Marzari

The extraction of chemical abundances of ionised nebulae from a limited spectral range is usually hampered by the lack of emission lines corresponding to certain ionic stages. So far, the missing emission lines have been accounted for by…

星系天体物理 · 物理学 2015-05-30 D. R. Goncalves , R. Wesson , C. Morisset , M. Barlow , B. Ercolano

The parameter $W_\mathrm{a}$, which characterizes nuclear spin-dependent parity violation effects within the effective molecular spin-rotational Hamiltonian, was computed for the electronic ground state of radium fluoride (RaF) and found to…

化学物理 · 物理学 2011-11-15 T. A. Isaev , S. Hoekstra , R. Berger

We report the crystal field levels of several newly-discovered rare-earth kagome compounds: $\rm{Nd_3Sb_3Mg_2O_{14}}$, $\rm{Nd_3Sb_3Zn_2O_{14}}$, and $\rm{Pr_3Sb_3Mg_2O_{14}}$. We determine the CEF Hamiltonian by fitting to neutron…

强关联电子 · 物理学 2018-10-10 A. Scheie , M. Sanders , J. Krizan , A. D. Christianson , V. O. Garlea , R. J. Cava , C. Broholm

We clarify the role of crystalline electric field (CEF) induced magnetic anisotropy in the ground state and spin-wave spectrum of cubic rare-earth materials with dominating isotropic magnetic exchange interactions. In particular we study…

强关联电子 · 物理学 2009-10-31 Gennadi Uimin , Wolfram Brenig

A model for crystal field triplet ground states on rare earth or actinide ions with dipolar and quadrupolar couplings to conduction electrons is studied for the first time with renormalization group methods. The quadrupolar coupling leads…

强关联电子 · 物理学 2009-10-31 Mikito Koga , Gergely Zarand , Daniel L. Cox
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