Search results for "Fig"

Psi4: an open-source ab initio electronic structure program

2011

The Psi4 program is a new approach to modern quantum chemistry, encompassing Hartree–Fock and density-functional theory to configuration interaction and coupled cluster. The program is written entirely in C++ and relies on a new infrastructure that has been designed to permit high-efficiency computations of both standard and emerging electronic structure methods on conventional and high-performance parallel computer architectures. Psi4 offers flexible user input built on the Python scripting language that enables both new and experienced users to make full use of the program's capabilities, and even to implement new functionality with moderate effort. To maximize its impact and usefulness, …

Reflections on the Nature of the Periodic Table of the Elements: Implications in Chemical Education

2014

The periodic table of the elements (PTE) results essential to understand our nature and place in the whole of beings. The same happens with our food, drugs, materials, etc. A series of questions were asked to introduce PTE and provide answers. The ideas in PTE should be valued by the number of questions that they generate. The PTE was related to electron configurations. The emergence of elements (nucleosynthesis) in physics was explained. The PTE results essential to understand our nature and place in the whole of beings. The same happens with our food, drugs, materials, etc. Schwarz and Rich asked a series of questions (Qs) to introduce PTE and provided answers. The ideas on PTE should be …

WITHIN-TEAM COMPETITION IN THE MINIMUM EFFORT COORDINATION GAME

2006

.  We report the results of an experiment on a continuous version of the minimum effort coordination game. The introduction of within-team competition significantly increases effort levels relative to a baseline with no competition and increases coordination relative to a secure treatment where the pay-off-dominant equilibrium strategy weakly dominates all other actions. Nonetheless, within-team competition does not prevent subjects from polarizing both in the efficient and the inefficient equilibria.

Long-term stability of phase-separated half-Heusler compounds

2015

Half-Heusler (HH) compounds have shown high figure of merit up to 1.5. Here, we address the long-term stability of n- and p-type HH materials. For this purpose, we investigated HH materials based on the Ti0.3Zr0.35Hf0.35NiSn-system after 500 cycles (1700 h) from 373 to 873 K. Both compounds exhibit a maximum Seebeck coefficient of |α|≈ 210 μV K(-1) and a phase separation into two HH phases. The dendritic microstructure is temperature resistant and upon cycling the changes in the microstructure are so marginal that the low thermal conductivity values (κ4 W m(-1) K(-1)) could be maintained. Our results emphasize that phase-separated HH compounds are suitable low cost materials and can lead to…

Large thermoelectric figure of merit in hexagonal phase of 2D selenium and tellurium

2020

Resolving the true band gap of ZrNiSn half-Heusler thermoelectric materials

2015

N-type XNiSn (X = Ti, Zr, Hf) half-Heusler (HH) compounds possess excellent thermoelectric properties, which are believed to be attributed to their relatively high mobility. However, p-type XNiSn HH compounds have poor figures of merit, zT, compared to XCoSb compounds. This can be traced to the suppression of the magnitude of the thermopower at high temperatures. E_g = 2eS_(max)T_(max) relates the band gap to the thermopower peak. However, from this formula, one would conclude that the band gap of p-type XNiSn solid solutions is only one-third that of n-type XNiSn, which effectively prevents p-type XNiSn HHs from being useful thermoelectric materials. The study of p-type HH Zr_(1−x)Sc_xNiSn…

Configurational landscape of chiral iron(II) bis(phosphane) complexes

2020

[EN] The reaction of a chiral [FeH(¿2-H2){(R,R)-Me-DuPhos}2]+ ((R,R)-Me-DuPhos = (¿)-1,2-bis[(2R,5R)-2,5-dimethylphospholano]benzene) complex with ethers and halides is investigated by NMR techniques. From this study, it is apparent that dihydrogen ligand exchange by poorly-coordinating donor molecules, such as THF or Et2O, is feasible under mild conditions. The cis-[FeH(THF-d8){(R,R)-Me-DuPhos}2]+ complex is identified as the product in THF-d8 solution. A mixture of cis- and trans-[FeH(ether){(R,R)-Me-DuPhos}2]+ isomers is obtained after the addition of small quantities of THF or Et2O to a CD2Cl2 solution of [FeH(¿2-H2){(R,R)-Me-DuPhos}2]+. The reaction of [FeH(¿2-H2){(R,R)-Me-DuPhos}2]+ w…

The two-dimensional iron(ii)–thiocyanate–4,4′-bipyridine coordination network

2010

The crystal structures of eight solvates of {Fe(4,4′-bipyridine)2(NCS)2}n have been determined. All of them contain a layered iron–bipyridine–thiocyanate framework formed from approximately square infinite two-dimensional (4,4) iron–bipyridine grids, with the solvent molecules hosted between adjacent layers. All the structures contain the iron(II) centres in the high-spin electronic configuration, and magnetic susceptibility measurements on the toluene and nitrobenzene solvates do not reveal any spin-crossover behaviour.

The ultimate message : a study of medieval tombstones in ducal Burgundy : 12th-16th centuries

2011

The tombstone has long been neglected by historians. As obituaries and wills, tombstones reveal as much the relationship of the deceased to death that the management of their memory by their heirs. This study first shows the wealth of medieval Burgundy graves goods. Typological diversity adds to the richness of iconography with large amounts of effigial monuments. Tombs materialize burial of prestige. Originally reserved for prelates and princes, burial ad ecclesiam progressively extended to the feudal aristocracy and the bourgeoisie. The location and the materialization of a burial monument also reflect the evolution of medieval piety. Epigraphy and iconography show the mutation of "gothic…

Efficient Design of Waveguide Manifold Multiplexers Based on Low-Order EM Distributed Models

2015

In this paper, a new systematic technique to design manifold-coupled multiplexers in waveguide technology is proposed. The new technique uses generalized low-order electromagnetic (EM) distributed models, which constitute a half-way point between the fast, but imprecise, analytical models, and the more accurate, but costly, full-wave EM models. The method can be applied to contiguous and noncontiguous channel multiplexers, in both E-plane or H-plane configurations. This paper covers the complete design procedure for manifold multiplexers, starting from the required specifications and finishing with the physical dimensions. After explaining the general design technique for multiplexers with …