Generating and grading 34 Optimised Norm-Conserving Vanderbilt Pseudopotentials for Actinides and Super Heavy Elements in the PseudoDojo

In the last decades, material discovery has been a very active research field driven by the necessity of new materials for different applications. This has also included materials incorporating heavy elements, beyond the stable isotopes of lead. Most of actinides exhibit unique properties that make them useful in various applications. Further, new heavy elements, taking the name of super-heavy elements, have been synthesized, filling previously empty space of Mendeleev periodic table. Their chemical bonding behaviour, of academic interest at present, would also benefit of state-of-the-art modelling approaches. In particular, in order to perform first-principles calculations with planewave basis sets, one needs corresponding pseudopotentials. In this work, we present a series of fully-relativistic optimised norm-conserving Vanderbilt pseudopotentials (ONCVPs) for thirty-four actinides and super-heavy elements. The scalar relativistic version of these ONCVPs is tested by comparing equations of states for crystals, obtained with \textsc{abinit} 9.6, with those obtained by all-electron zeroth-order regular approximation (ZORA) calculations performed with the Amsterdam Modelling Suite BAND code. $\Delta$-Gauge and $\Delta_1$-Gauge indicators are used to validate these pseudopotentials. This work is a contribution to the PseudoDojo project, in which pseudopotentials for the whole periodic table are developed and systematically tested. The fully-relativistic pseudopotential files (i.e. including spin-orbit coupling) are available on the PseudoDojo web-interface pseudo-dojo.org under the name NC FR (ONCVPSP) v4.x. Pseudopotentials are made available in psp8 and UPF2 formats, both convenient for \textsc{abinit}, the latter being also suitable for Quantum ESPRESSO

Dirac Surface States and Nature of Superconductivity in Noncentrosymmetric BiPd

In non-magnetic bulk materials, inversion symmetry protects the spin degeneracy. If the bulk crystal structure lacks a centre of inversion, however, spin-orbit interactions lift the spin degeneracy, leading to a Rashba metal whose Fermi surfaces exhibit an intricate spin texture. In superconducting Rashba metals a pairing wavefunction constructed from these complex spin structures will generally contain both singlet and triplet character. Here we examine the possible triplet components of the order parameter in noncentrosymmetric BiPd, combining for the first time in a noncentrosymmetric superconductor macroscopic characterization, atomic-scale ultra-low-temperature scanning tunnelling spectroscopy, and relativistic first-principles calculations. While the superconducting state of BiPd appears topologically trivial, consistent with Bardeen-Cooper-Schrieffer theory with an order parameter governed by a single isotropic s-wave gap, we show that the material exhibits Dirac-cone surface states with a helical spin polarization.Comment: replaced by published versio

A Multireference Density Functional Approach to the Calculation of the Excited States of Uranium Ions

An accurate and efficient hybrid Density Functional Theory (DFT)/Multireference Configuration Interaction (MRCI) model for computing electronic excitation energies in heavy element atoms and molecules was developed. This model incorporated relativistic effects essential for accurate qualitative and quantitative spectroscopic predictions on heavy elements, while simultaneously removing spin-multiplicity limitations inherent in the original model on which it is based. This model was used to successfully compute ground and low-lying electronic states for atoms in the first two rows of the period table, which were used for calibration. Once calibrated, calculations on carbon monoxide, bromine fluoride, the bromine atom, uranium +4 and +5 ions and the uranyl (UO22+) ion showed the model achieved reductions in relative error with respect to Time Dependent Density Functional Theory (TDDFT) of 11-42%, with a corresponding reduction in computational effort in terms of MRCI expansion sizes of a factor of 25-64

Topical meeting on Condensed-matter Chemistry on Actinides: The Kumatori meeting 2021

Topical meeting on Condensed-matter Chemistry on Actinides : The Kumatori meeting 2021, Feb. 10th, 2021@ZoomThis report is published to preserve the discussions of“the Kumatori 2021”conference held on Feb. 10, 2021.Chapter 1 Program [1]Chapter 2 Opening Remarks [4]Chapter 3 Presentation Materials [8]3.1 H. Yamagami（Kyoto Sangyo Univ.）, Objectives of this meeting [9]3.2 Y. Haga（ASRC, JAEA）, Uranium-based inter metallics with layered structure: characterization and magnetism [11]3.3 K. Ishida（Dept. Phys., Kyoto Univ.）, Superconducting Spin Susceptibility of UTe₂ [13]3.4 T. Yaita（SPring-8, JAEA）, Recent activities of Actinide Chemistries in the Materials Sciences Rsearch Center of JAEA [17]3.5 N. Ishikawa（Dept. Chem., Osaka Univ.）, Observation of interaction between 5f electronic system and photo-excited cyclic π system [21]3.6 T. Suzuki（Nagaoka Univ. Tech.）, Fundamental Study for Precise Analysis of Actinides in Hardly Soluble Substances Containing Uranium Oxides [25]3.7 K. Washiyama（Fukushima Medical University）, Current status and prospects of domestic supply of alpha-emitting radionuclides [29]3.8 Y. Kawabata（KURNS, Kyoto Univ.）, Current status and future plans of our institute [34]3.9 T. Yamamura（KURNS, Kyoto Univ.）, Actinide researches using KUR hot-lab [35]3.10 M. Suzuki（KURNS, Kyoto Univ.）, The Future of Cyclotron-Based BNCR Research [38]3.11 T. Kitazawa（Dept. Chem., Toho Univ.）, Synthesis and Crystal Structures of Three New Complexes Constructed with Uranyl(VI)-acetylacetonate and Uranyl(VI)-nitrate [43]3.12 T. Yoshimura（IRS, Osaka Univ.）, Preparation of guidelines for evaluation to ensure safety in the use of short-lived unsealed radioisotopes [50]3.13 H. Amitsuka（Hokkaido Univ.）, Odd Parity Multipole Ordering in Uranium Compounds [52]3.14 T. Yanagisawa（Hokkaido Univ.）, Electric Quadrupolar Contributions in the Magnetic Phases of UNi₄B [56]3.15 M. Manjum（Dept. Appl. Chem., Keio Univ.）, Electrochemical Formation of Samarium and Samarium-Cobalt Nanoparticles in a Pyrrolidinium-based Ionic Liquid [60]3.16 T. Nomoto（Tokyo Inst. Tech.）, Drug delivery using functional polymer-conjugates [63]3.17 A. P. Goncalves（Universidade Lisboa, Portugal）, On the U-Fe-Ge system and its compounds [65]3.18 A. S. P. Gomes（Universite de Lille, France）, Electronic structure of actinide systems from relativistic correlated and quantum embedding approaches [72]3.19 R. Caciuffo（EU JRC, Karlsruhe, Germany）, Radioisotopes for medical applications [77]Chapter 4 Break Session [81]4.1 Break Session 1 [83]4.1.1 H. Shishido（Tohoku Univ.）, Proposals for the advanced nuclear fuel cycle by introducing a fusion reactor [83]4.1.2 M. Nakase（Tokyo Inst. Tech.）, Development and characterization of phthalocyanine derivatized ligands for recognition and complexation of light Actinide elements [87]4.1.3 H. Nakai（Kindai Univ.）, Development of ligands for new actinide complexes [89]4.1.4 C. Tabata（Kyoto Univ.）, Crystal structure and magnetic property of uranium phthalocyanine complexes [93]4.1.5 Y. Kasamatsu（Osaka Univ.）, Co-precipitation experiment of group 2 elements with barium hydrosulfate toward chemical study of No [98]4.1.6 K. Shirasaki（Tohoku Univ.）, Extraction of strontium from aqueous solutions intoHFCusing dicyclohexano-18-crown-6 and perfluorinated polyethylene glycol derivative [102]4.1.7 Y. Sekiguchi（CRIEPI）, Thermodynamic estimation of vaporization of CsI dissolved in LiFNaF-KF molten salt [104]4.1.8 F. Kon（Hokkaido Univ.）, Observation of Antiferromagnetic Order in the Heavy-Fermion Compound UIr₂Ge₂ - Resonant X-ray Scat-tering [109]4.1.9 A. Sato（Tokyo Met. Univ.）, Theoretical study on isotope fractionation in uraninite [112]4.1.10 Y. Kitawaki（Kyoto Sangyo Univ.）, Orbital magnetization in many-electron systems described by spin-orbital-polarized coupled Dirac equation [116]4.2 Break Session 2 [119]4.2.1 T. Fukuda（JAEA）, Present status of the study on energy conversion using actinides in radioactive wastes [119]4.2.2 T. Oda（Kyoto Univ.）, Slow dynamics study by neutron resonance spin echo spectromete [121]4.2.3 A. Sunaga（Kyoto Univ.）, Theoretical study of the linearity of uranyl molecule based on relativistic correlation method [125]4.2.4 M. Nogami（Kindai Univ.）, Change in precipitation ability of treated cyclic urea compounds for selective precipitation of U(VI) species [128]4.2.5 Y. Homma（Tohoku Univ.）, Mossbaure spectroscopy of the Eu-based skyrmion compounds EuPtSi and EuAl₄ [134]4.2.6 K. Nagata（Osaka Univ.）, Synthesis of Actinium Complex with a Macrocycle Having Pyridine Phosphonate Pendant Arms [138]4.2.7 T. Yamane（Nagaoka Univ. Tech.）, Electrochemical method of minor actinide recovery from nitric acid solution using Ga liquid electrode and ionic liquid [140]4.2.8 M. Yokota（Kindai Univ.）, Adsorptivity of monoamide polymer adsorbent impregnated with PPTPT to metal ions in neutral aqueous solutions for recovery of uranium in seawater [144]4.2.9 K. Mori（Kyoto Univ.）, Introduction of Versatile Compact Neutron Diffractometer (VCND) at B-3 Beam Port of KUR [147]4.2.10 T. Kobayashi（SPring-8, JAEA）, XAFS study on the the aged deterioration of a simulated fuel debris [148]Chapter 5 Concluding Remarks [152]5.1 S. Kambe（ASRC, JAEA）, Concluding Remarks 1 [152]5.2 H. Yamagami（Kyoto Sangyo Univ.）, Concluding Remarks 2 [154]Chapter 6 Summary of Discussion [155]Chapter 7 List of Participants [156]Chapter 8 Photos of the workshop [158

The periodic table and the physics that drives it

As the International Year of the Periodic Table came to an end in 2019, the authors reflect on the chemistry and physics that drive the periodic table of the elements. This includes aspects of periodic trends, relativistic electronic-structure theory, nuclear-structure theory and the astrophysical origin of the elements. Mendeleev's introduction of the periodic table of elements is one of the most important milestones in the history of chemistry, as it brought order into the known chemical and physical behaviour of the elements. The periodic table can be seen as parallel to the Standard Model in particle physics, in which the elementary particles known today can be ordered according to their intrinsic properties. The underlying fundamental theory to describe the interactions between particles comes from quantum theory or, more specifically, from quantum field theory and its inherent symmetries. In the periodic table, the elements are placed into a certain period and group based on electronic configurations that originate from the Pauli and Aufbau principles for the electrons surrounding a positively charged nucleus. This order enables us to approximately predict the chemical and physical properties of elements. Apparent anomalies can arise from relativistic effects, partial-screening phenomena (of type lanthanide contraction) and the compact size of the first shell of everyl-value. Further, ambiguities in electron configurations and the breakdown of assigning a dominant configuration, owing to configuration mixing and dense spectra for the heaviest elements in the periodic table. For the short-lived transactinides, the nuclear stability becomes an important factor in chemical studies. Nuclear stability, decay rates, spectra and reaction cross sections are also important for predicting the astrophysical origin of the elements, including the production of the heavy elements beyond iron in supernova explosions or neutron-star mergers. In this Perspective, we critically analyse the periodic table of elements and the current status of theoretical predictions and origins for the heaviest elements, which combine both quantum chemistry and physics.Peer reviewe

Large Noncollinearity and Spin Reorientation in the Novel Mn2RhSn Heusler Magnet

Noncollinear magnets provide essential ingredients for the next generation memory technology. It is a new prospect for the Heusler materials, already well known due to the diverse range of other fundamental characteristics. Here, we present a combined experimental and theoretical study of novel noncollinear tetragonal Mn2RhSn Heusler material exhibiting unusually strong canting of its magnetic sublattices. It undergoes a spin-reorientation transition, induced by a temperature change and suppressed by an external magnetic field. Because of the presence of Dzyaloshinskii-Moriya exchange and magnetic anisotropy, Mn2RhSn is suggested to be a promising candidate for realizing the Skyrmion state in the Heusler family

Accurate Prediction of Core Properties for Chiral Molecules using Pseudo Potentials

Pseudo potentials (PPs) constitute perhaps the most common way to treat relativity, often in a formally non-relativistic framework, and reduce the electronic structure to the chemically relevant part. The drawback is that orbitals obtained in this picture (called pseudo orbitals (POs)) show a reduced nodal structure and altered amplitude in the vicinity of the nucleus, when compared to the corresponding molecular orbitals (MOs). Thus expectation values of operators localized in the spatial core region that are calculated with POs, deviate significantly from the same expectation values calculated with all-electron (AE) MOs. This study describes the reconstruction of AE MOs from POs, with a focus on POs generated by energy consistent pseudo Hamiltonians. The method reintroduces the nodal structure into the POs, thus providing an inexpensive and easily implementable method that allows to use nonrelativistic, efficiently calculated POs for good estimates of expectation values of core-like properties. The discussion of the method proceeds in two parts: Firstly, the reconstruction scheme is developed for atomic cases. Secondly, the scheme is discussed in the context of MO reconstruction and successfully applied to numerous numerical examples. Starting from the equations of the state-averaged multi-configuration self- consistent field method, used for the generation of energy consistent pseudo potentials, the electronic spectrum of the many-electron Hamiltonian is linked to the spectrum of the effective one-electron Fock operator by means of various models systems. This relation and the Topp–Hopfield–Kramers theorem, are used to show the shape-consistency of energy-consistent POs for atomic systems. Shape-consistency describes POs that follow distinct AOs exactly outside a core-radius r_core . In the cases presented here, shape-consistency holds to a high degree and it follows that in atomic systems every PO has one distinct partner in the set of AOs. The overlap integral between these two orbitals is close to one, as it is determined mainly by the spatial orbital parts outside r_core . Expanding, e.g., a 5s PO in occupied AOs, the 5s AOs will have the highest contribution. The POs itself contains contributions from high-energy unoccupied AOs as well (e.g. 15s), which damp the nodal structure of the POs near the nucleus. Consequently, neglecting contributions from unoccupied orbitals in a projection of the POs reintroduces the nodal structure. This approach is not directly suitable for the reconstruction of MOs, as they often need to be expanded in a full set of AOs at each atomic center, including all unoccupied orbitals, to properly account for the electron density distribution in the molecule. However, it is shown that the occupied MOs are well described by occupied and low-energy unoccupied AOs only and a mapping of the POs onto a basis containing only these orbitals reconstructs the nodal structure of the MO. The approach uses only standard integrals available in most quantum chemistry programs. The computational cost of these integrals scales with N^2 , where N is the number of basis functions. The most time consuming step is a Gram-Schmidt orthogonalization, which scales in this implementation with MN^2 , M being the number of reconstructed orbitals. The reconstruction method is subsequently tested: Valence orbitals of atomic, closed-shell systems were reconstructed numerically exactly. The influence of numerical parameters is investigated using the molecule BaF . It is shown that the method is basis set dependent: One has to ensure that the PO basis can be expanded exactly in the basis of AOs. Violating this rule of thumb may degrade the quality of reconstructed orbitals. Additionally, the representation of MOs by a linear combination of occupied and unoccupied AOs is investigated. For the exemplary systems, the shells included in the fitting procedure of the PP were sufficient. Reconstruction of the alkaline earth monofluorides showed that periodic trends can be reconstructed as well. Scaling of hyperfine structure parameters with increasing atomic number is discussed. For hydrogenic atoms, the scaling should be linear, whereas small deviations from the linear behavior were observed for molecules. The scaling laws computed from reconstructed and reference orbitals were almost identical. In this context, the failure of commonly used relativistic enhancement factors beyond atomic number 100 is discussed. Applicability of the method is also tested on parity violating properties for which the main contribution is generated by the valence orbitals near the nucleus. Symmetry-independence of the method is shown by successful reconstruction of orbitals of the tetrahedral PbCl_4 and chiral NWHClF. The reliable reconstruction of chemical trends is shown with the help of the NWHClF derivatives NWHBrF and NWHFI. The study of chiral compounds as, e.g., NWHClF and its group 17 derivatives, which have been proposed as paradigm for the detection of parity-violation in chiral molecules, remains of great importance. Especially the direct determination of absolute configuration of chiral centers is still non-trivial. The author contributed to this field with a self-written molecular dynamics (MD) program to simulate Coulomb explosions and thus to provide an insight especially into the early explosion stages directly after an instantaneous multi-ionization of the molecule CHBrClF, comparable to experiments using the Cold Target Recoil Ion Momentum Spectroscopy (COLTRIMS) technique. An algorithm for the determination of the investigated molecule’s absolute configuration from time-of-flight data and detection locations of molecular fragments is included in the program. The program was used to generate experiment-equivalent data which allowed for the first time the investigation of non-racemic mixtures by the analysis routines of the experiment. The MD program includes harmonic and anharmonic bond potentials. A charge-exchange model can model partial charges in early phases of the Coulomb explosion. Furthermore, Born–Oppenheimer MD simulations and statistical models are used to explain the relative abundance of products belonging to competing reaction channels, as obtained by photoion coincidence measurements. Additionally, qualitative statements about reaction branching ratios are made by comparing the partition functions of involved degrees of freedom. Analytic equations for partition functions of simple models are used to provide a simple formula allowing fast estimates of reaction branching ratios