相关论文: Extraction of crystal-field parameters for lanthan…
The crystal field theory as explained by Abragam and Bleaney in their landmark 1970 book on transition-ion electron paramagnetic resonance remains a cornerstone in the development of luminescence applications and molecular magnets based on…
The effective crystal field Hamiltonian provides the key description of the electronic properties of single-ion magnets, but obtaining its parameters from ab initio computation is challenging. We introduce a simple approach to derive the…
The crystal field parameters of 13 trivalent lanthanide ions substituted for La in LaF$_3$ were calculated using the combination of the band structure and Wannier function calculations. Performing an atomic exact diagonalization with thus…
Parametrized crystal-field analyses are presented for both the six and seven fold coordinated, C$_{1}$ symmetry Sm$^{3+}$ centers in Y$_{2}$SiO$_{5}$, based on extensive spectroscopic data spanning the infrared to optical regions. Laser…
K$_2$YF$_5$ crystals doped with lanthanide ions have a variety of possible optical applications. Owing to the low symmetry of the system, the crystal structure cannot be unambiguously determined by x-ray diffraction. However,…
Using a recently developed method combining a nonspherical self-interaction corrected LDA+$U$ scheme and an on-site multi-body Hamiltonian [Phys.\ Rev.\ B 83, 085106 (2011)], we calculate the crystal field parameters and crystal field (CF)…
We discuss recent progress and future prospects for the analysis of the 4f${N-1}$5d excited states of lanthanide ions in host materials. Ab-initio calculations for Ce$^{3+}$ in LiYF$_4$ are used to estimate crystal-field and spin-orbit…
Calculated energy levels from recent \emph{ab initio} studies of the electronic structure of SrCl$_{2}$:Yb$^{2+}$ and CsCaBr$_{3}$:Yb$^{2+}$ are fitted with a semi-empirical "crystal-field" Hamiltonian, which acts within the model space…
We use complementary optical spectroscopy methods to directly measure the lowest crystal-field energies of the rare-earth quantum magnet LiY$_{1-x}$Ho$_{x}$F$_{4}$, including their hyperfine splittings, with more than 10 times higher…
Fifteen parameters characterizing the crystal field of rare-earth ions in the RMO$_3$ perovskites (R = Pr, Nd, M = Ga, Co) are calculated by expanding the local Hamiltonian expressed in the basis of Wannier functions into a series of…
We present a method of calculating crystal field coefficients of rare-earth/transition-metal (RE-TM) magnets within density-functional theory (DFT). The principal idea of the method is to calculate the crystal field potential of the yttrium…
A method to calculate the crystal field parameters {\it ab initio} is proposed and applied to trivalent rare earth impurities in yttrium aluminate and to Tb$^{3+}$ ion in TbAlO$_3$. To determine crystal field parameters local Hamiltonian…
A successful and commonly used ab initio method for the calculation of crystal field levels and magnetic anisotropy of lanthanide complexes consists of spin-adapted state-averaged CASSCF calculations followed by state interaction with…
Using the recently developed method we calculate the crystal field parameters in yttrium and lutetium aluminum garnets doped with seven trivalent Kramers rare-earth ions. We then insert calculated parameters into the atomic-like Hamiltonian…
In the framework of the LDA+U approximation we propose the direct way of calculation of crystal-field excitation energy and apply it to La and Y titanates. The method developed can be useful for comparison with the results of spectroscopic…
The formation of heterogeneous lanthanide-ion clusters in CaF$_2$ was investigated experimentally and computationally. CaF$_2$ nanoparticles co-doped with 20~mol\% Yb$^{3+}$ and 2~mol\% Ln$^{3+}$ (Ln$^{3+}$ = Ce$^{3+}$, Pr$^{3+}$,…
We introduce PyCrystalField, a Python software package for calculating single-ion crystal electric field (CEF) Hamiltonians. This software can calculate a CEF Hamiltonian \textit{ab initio} from a point charge model for any transition or…
We discuss the calculation of crystal field splittings using Wannier functions and show how the ligand field contributions can be separated from the bare Coulomb contribution to the crystal field by constructing sets of Wannier functions…
Accurate models of alkali and halide ions in aqueous solution are necessary for computer simulations of a broad variety of systems. Previous efforts to develop ion force fields have generally focused on reproducing experimental measurements…
This work is aimed at the multi-configuration Hartree-Fock calculations of the 6s ionization energies of lanthanides with configurations [Xe]4f^{N}6s^{2}. Authors have used the ATSP MCHF version in which there are new codes for calculation…