Author: Harry Ramanantoanina

Electronic Structure of Lr+ (Z = 103) from Ab Initio Calculations

Atoms 10(2), 48 (2022). doi:10.3390/atoms10020048

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2p x-ray absorption spectroscopy of 3d transition metal systems

Abstract This review provides an overview of the different methods and computer codes that are used to interpret 2p x-ray absorption spectra of 3d transition metal ions. We first introduce the basic parameters and give an overview of the methods used. We start with the semi-empirical multiplet codes and compare the different codes that are available. A special chapter is devoted to the user friendly interfaces that have been written on the basis of these codes. Next we discuss the first principle codes based on band structure, including a chapter on Density Functional theory based approaches. We also give an overview of the first-principle multiplet codes that start from a cluster calculati…

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A Progress Report on Laser Resonance Chromatography

Atoms 10(3), 87 (2022). doi:10.3390/atoms10030087

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Electronic structure of Rf + ( Z = 104 ) from ab initio calculations

We report calculation of the energy spectrum and the spectroscopic properties of the superheavy element ion: Rf+. We use the four-component relativistic Dirac-Coulomb Hamiltonian and the multireference configuration interaction model to tackle the complex electronic structure problem that combines strong relativistic effects and electron correlation. We determine the energies of the ground and the low-lying excited states of Rf+, which originate from the 7s26d1,7s16d2,7s27p1, and 7s16d17p1 configurations. The results are discussed vis-à-vis the lighter homolog Hf+ ion. We also assess the uncertainties of the predicted energy levels. The main purpose of the presented calculations is to provi…

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Electronic structure of Rf+ (Z=104) from ab initio calculations

We report calculation of the energy spectrum and the spectroscopic properties of the superheavy element ion: ${\mathrm{Rf}}^{+}$. We use the four-component relativistic Dirac-Coulomb Hamiltonian and the multireference configuration interaction model to tackle the complex electronic structure problem that combines strong relativistic effects and electron correlation. We determine the energies of the ground and the low-lying excited states of ${\mathrm{Rf}}^{+}$, which originate from the $7{s}^{2}6{d}^{1},\phantom{\rule{0.28em}{0ex}}7{s}^{1}6{d}^{2},\phantom{\rule{0.28em}{0ex}}7{s}^{2}7{p}^{1}$, and $7{s}^{1}6{d}^{1}7{p}^{1}$ configurations. The results are discussed vis-\`a-vis the lighter h…

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Understanding the Stabilization and Tunability of Divalent Europium 2.2.2B Cryptates

Lanthanides such as europium with more accessible divalent states are useful for studying redox stability afforded by macrocyclic organic ligands. Substituted cryptands, such as 2.2.2B cryptand, that increase the oxidative stability of divalent europium also provide coordination environments that support synthetic alterations of Eu(II) cryptate complexes. Two single crystal structures were obtained containing nine-coordinate Eu(II) 2.2.2B cryptate complexes that differ by a single coordination site, the occupation of which is dictated by changes in reaction conditions. A crystal structure containing a [Eu(2.2.2B)Cl]+ complex is obtained from a methanol-THF solvent mixture, while a methanol-…

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Quantitative analysis of rhenium in irradiated tungsten

Abstract Pure tungsten (W), irradiated to 3.5 dpa in a target of the Swiss neutron spallation source (SINQ), was characterized using high-sensitivity HPGe gamma ray spectroscopy to identify the present radionuclides. Synchrotron X-ray absorption spectroscopy was used to quantify the amount of Re produced in the irradiated W. An atomic concentration of 0.61% Re in the irradiated W was determined from the height of the L3-edge X-ray absorption edge jump. Analysis of the local atomic structure from the extended X-ray absorption fine structure (EXAFS) spectra indicates that rhenium (Re) produced in the system is mainly coordinated by W atoms and partly coordinated by void defects. First-princip…

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Influence of Outer-Sphere Anions on the Photoluminescence from Samarium(II) Crown Complexes.

Three samarium(II) crown ether complexes, [Sm(15-crown-5)2]I2 (1), [Sm(15-crown-5)2]I2·CH3CN (2), and [Sm(benzo-15-crown-5)2]I2 (3), have been prepared via the reaction of SmI2 with the corresponding crown ether in either THF or acetonitrile in good to moderate yields. The compounds have been characterized by single crystal X-ray diffraction and a variety of spectroscopic techniques. In all cases, the Sm(II) centers are sandwiched between two crown ether molecules and are bound by the five etheric oxygen atoms from each crown ether to yield 10-coordinate environments. Despite the higher symmetry crystal class of 1 (R3c), the samarium center resides on a general position, whereas in 2 and 3 …

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