Spanish Initiative Research Articles

Study of effect of hydrostatic pressure on structural, electronic and magnetic properties of In0.75Mn0.25P using density functional theory

In this paper, the investigation of effect of hydrostatic pressure on the structural, electronic and magnetic properties of In0.75Mn0.25P Diluted Magnetic Semiconductor in Zinc Blende (B3) phase at 0 GPa–26 GPa pressure range is done using first principal calculations as implemented in Spanish Initiative for Electronic Simulations with Thousands of Atoms (SIESTA) code.The theoretical investigation of electronic and magnetic properties of this compound represents that the compound is half-metallic ferromagnet and show 100% spin polarization at different values of pressure. It is found that forbidden energy band gap increases with increase in pressure as spin polarized band structures experience changes with applied pressure. The calculated results show that lattice constant and volume of compound decreases along-with increase in induced local magnetic moments values of non-magnetic indium and phosphorus atoms with applied pressure.

EP1.16-01 A Spanish Initiative to Know the Unmet Needs of Women with Lung Cancer: "Circulos Program"

EP1.16-01 A Spanish Initiative to Know the Unmet Needs of Women with Lung Cancer: "Circulos Program"

Precision medicine in relapsed or refractory pediatric solid tumors: a collaborative Spanish initiative

BackgroundUnderstanding pediatric cancer biology is a huge challenge in continuous development that is currently being implemented into the clinical practice thanks to the new high throughput technologies integrated by personalized medicine.We present the results of the Precision Medicine program for children and adolescents with solid tumors in relapse/progression carried out in University La Fe Hospital (Valencia) from 2014. This is the first Spanish experience in precision medicine published in pediatric oncology.MethodsStudy enrollment was offered to all patients having a refractory or relapsed solid tumor and an available biopsy treated in La Fe Hospital (Valencia, Spain) or in other Spanish pediatric oncologic center. Eighty four patients were finally studied. The commercial Human Comprehensive Cancer GeneReadDNAseq Targeted genes Panel (Qiagen©) was sequenced in fresh/frozen samples. Variants considered pathogenic or likely pathogenic were classified using the algorithm published by Parsons et al. based on perceived clinical utility.ResultsThirteen of 84 patients (15%) received therapeutic recommendations due to an actionable variant detected and three patients received prognosis information based on sequencing results.ConclusionsPrecision medicine projects based on targetable gene panel approximations can obtain translatable information to pediatric patients with reasonable efforts. This approach lowers economic expenses and reduces time of response with respect to whole exome sequencing. Since the translation to the clinical practice is the main objective of these projects, limiting the number of relatively well-known biological markers will allow us to transfer similar amount of information with less economic and human effort.

Olfactory proteotyping: towards the enlightenment of the neurodegeneration.

Olfactory proteotyping: towards the enlightenment of the neurodegeneration.

The PERCEBES project: science for the spatial management of the stalked barnacle fishery in the Atlantic Arc

The PERCEBES project: science for the spatial management of the stalked barnacle fishery in the Atlantic Arc

The Spanish Ion Channel Initiative (SICI) Consortium: Ten Years (2008–2018) of a Network of Excellence on Ion Channel Research

The Spanish Ion Channel Initiative consortium (SICI, http://sici. [...].

PASTA: Python Algorithms for Searching Transition stAtes

Chemical reactions are often associated with an energy barrier along the reaction pathway which hinders the spontaneity of the reaction. Changing the energy barrier along the reaction pathway allows one to modulate the performance of a reaction. We present a module, Python Algorithms for Searching Transition stAtes (PASTA), to calculate the energy barrier and locate the transition state of a reaction efficiently. The module is written in python and can perform nudged elastic band, climbing image nudged elastic band and automated nudged elastic band calculations. These methods require the knowledge of the potential energy surface (and its gradient along some direction). This module is written such that it works in conjunction with density functional theory (DFT) codes to obtain this information. Presently it is interfaced with three well known DFT packages: Vienna Ab initio Simulation Package (VASP), Quantum Espresso and Spanish Initiative for Electronic Simulations with Thousands of Atoms (SIESTA). This module is easily extendable and can be interfaced with other DFT, force-field or empirical potential based codes. The uniqueness of the module lies in its user-friendliness. For users with limited computing resources, this module will be an effective tool as it allows to perform the calculations image by image. On the other hand, users with plentiful computing resources (such as users in a high performance computing environment) can perform the calculations for large number of images simultaneously. This module gives users complete flexibility, thereby enabling them to perform calculations on large systems making the best use of the available resources. Program summaryProgram Title: PASTAProgram files doi:http://dx.doi.org/10.17632/rv7fdm5gkf.1Licensing provisions: BSD 3-clauseProgramming language: PythonExternal routines/libraries: numpy, matplotlibNature of problem: Most of the reactions have an energy barrier on their reaction pathway. This energy barrier affects the progress of the reaction.Solution method: We implement the NEB, CI-NEB and AutoNEB method to locate transition state and estimate the energy barrier. Our module works with density functional theory codes: VASP, SIESTA and Quantum Espresso presently.

Study of structural, electronic, magnetic, and elastic properties of GaP and Ga0.75X0.25P (where X = Cr, Mn, and Fe) using DFT studies

We investigate the structural, electronic, magnetic, and elastic properties of Ga1−x Cr x P, Ga1−x Mn x P, and Ga1−x Fe x P diluted magnetic semiconductor (x = 0.25) in zinc blende (B3) phase. The calculations have been performed using Density functional theory as implemented in the Spanish Initiative for Electronic Simulations with Thousands of Atoms code using local density approximation (LDA) and LDA + U (U = 3) as exchange-correlation (XC) potential. The study of electronic structures and magnetic properties shows that doping of Cr/Mn transition metal atom in GaP results in the induction of ferromagnetism and develops metallic character and Fe-doped GaP shows semiconductor behavior when systems are studied using LDA + U. Calculated results are in good agreement with previous theoretical and experimental data.

Spanish Initiative for the Automation in Urban Transport: AutoMOST

The progressive automation of transport will imply a new paradigm in mobility, which will profoundly affect people, logistics of goods, as well as other sectors dependent on transport. It is precise within this automation where the development of new driving technologies is going to cause a great impact on the mobility of the near future, and that will have an effect on the economic, natural and social environment. It is therefore a primary issue at the global level, as it is reflected in the work programs of the European Commission in relation to the road transport [1] [2]. Thus, the size impact is caused by the following novelties and advantages: 1) Safety: Accidents reduction caused by human error; 2) Efficiency increase in transportation, both in energy consumption and time; 3) Comfort for users and professionals who will increase their operational availability to execute other more valuable tasks, both for them and enterprises; 4) Social Inclusion: enabling mobility easily for everybody during more time; 5) Accessibility, to get to city centers and other difficult reach places. It should be noted that the economic impact projected for automated driving for the years to come ranges up to €71 bn in 2030, when estimated global market for automated vehicles is 44 million vehicles, as is reflected in document Automated Driving Roadmap by ERTRAC [3], European Road Transport Research Advisory Council (http://www.ertrac.org/uploads/documentsearch/id38/ERTRAC_Automated-Driving-2015.pdf). As background that already anticipates these im-provements, the Advance Driver Assistance System (ADAs) have already showed the safety increase in the last ten years, but always maintain a leading role for the driver. Related to the efficiency increase, automated driving offers great opportunities for those companies where mobility is a key factor in operating costs, and affects the whole value chain. The project opportunity is consistent with ERTRAC vision, especially in applications focused on the urban environment [4], where it is expected a deployment of the technology of high level automation in an immediate future. This is possible by the potential to incorporate smart infrastructure to improve guidance and positioning, as well as lower speed, which eases its progressive deployment. The objective of AutoMOST is developing technologies for the automation of vehicles in urban transport and industrial applications, to increase significantly the efficiency, safety and environmental sustainability. More specifically, AutoMOST will allow the implementation of shared control systems (Dual-Mode) [5] for future automated vehicles that allow the services operate more efficiently and flexibly, in a context of intelligent and connected infrastructures.

Small Al and Ga clusters trapped inside the Bucky-ball (C60) — A DFT study

In the present paper, we have done a systematic study of structural and electronic properties of endohedrally doped C[Formula: see text] with Al and Ga atoms using density functional theory (DFT) with the help of Spanish initiative for electronic simulation with thousands of atoms (SIESTA) package in the generalized gradient approximation (GGA). The parameters calculated are binding energy/dopant atom, vertical ionization potential (VIP), vertical electron affinity (VEA), HOMO–LUMO gap and charge transfer. The stabilized ground state structures of Al[Formula: see text]@C[Formula: see text] ([Formula: see text]–10) and Ga[Formula: see text]@C[Formula: see text] ([Formula: see text]–10) show that a maximum of nine Al or Ga atoms can be encapsulated in C[Formula: see text] without distorting the cage significantly. Mulliken charge analysis shows an electron transfer from the metal dopant to the cage surface, except for Al[Formula: see text] ([Formula: see text]–10). The endohedral metal clusters adopt a more compact shape when inside C[Formula: see text], compared to its free-state configuration and its symmetry. The study of HOMO–LUMO gap reveals that the gap decreases with the increase in number of dopant atoms inside C[Formula: see text].

I want it and I want it now! An initial approach to the Spanish instant payments solution

Immediacy has become the norm. It is therefore essential that the provision of payment services recognises this reality. Payment service users are increasingly demanding new functionalities alongside improved and faster payment services. As new players arrive on the scene, numerous initiatives are flourishing in an attempt to meet these expectations. Traditional payment services providers face an important challenge, but a wait-and-see attitude is not the answer. This paper describes the basic features of the Spanish instant payments initiative launched in 2016 to respond to this need. It reviews the origins and objectives of this cooperative solution led by the banking industry, the possible use cases and the timetable for its implementation. It also sheds some light on the various stakeholders involved, the key issues and challenges in the development of the initiative, and the foreseen potential benefits.

LDA + U Study of Induced Half Metallicity in Cr-Doped GaN

Half-metallic ferromagnetism in the Ga1 − xCrxN compound at different concentrations, x = 25, 12.5 and 6.25 %, have been investigated using density functional theory as implemented in code Spanish Initiative for Electronic Simulations with Thousands of Atoms (SIESTA) using LDA + U as exchange-correlation (XC) potential, to find out the possibility of new diluted DMSs. The outcomes reveal that transition metal atom (Cr) doping in GaN induces ferromagnetism. The 3d levels of the TM ion originate a half-metallic gap at the Fermi level in the majority spin channel for all concentrations. Moreover, diluted magnetic semiconductor compounds retain the half-metallic nature at all concentrations, i.e., x = 0.25, 0.125 and 0.0625, with 100 % spin polarization at the Fermi level (EF). The total magnetic moment of these compounds is due to Cr-3d states, and the existence of a small magnetic moment on Ga and N, non-magnetic atoms, for all doping concentrations is a consequence of p-d hybridization of Cr-d and N-p states. The calculated values of s-d exchange constant N α and p-d exchange constant N βconfirm the ferromagnetic character of the Cr-doped GaN compound.

Hybrid Hamiltonian and Green's Function Approach for Studying Native Point Defect Levels in Semiconductor Compounds and Superlattices

We have developed a hybrid method that can be applied to study isolated defects in semiconductor compounds and superlattices. The method is a combination of (1) a long-range tight-binding (TB) Hamiltonian, (2) a first-principles Hamiltonian, and (3) a Green’s function (GF) formalism. The calculation of the GF requires accurate energy band structure, wave functions, and defect potentials. The TB Hamiltonian with sp3 orbitals basis ensures accurate band gaps and band masses while providing the functional form for the wave functions. We calculated the band gaps of InAs/GaSb and InAs/InAsSb strained-layer superlattices and found them to agree well with measurements. The change in potentials caused by native point defects (NPDs) was obtained from a first-principles method using Spanish Initiative for Electronic Simulations with Thousands of Atoms, which also uses sp3 basis. We describe the method of calculating NPD energy levels in compounds and superlattices, obtain some defect levels in GaAs, InAs, InSb, and GaSb compounds, and provide details of the NPD-level calculations.

DFT Study of Diluted Magnetic Semiconductor Cd1-xCrxS at x=3.125%

We investigate the structural, Electronic and Magnetic properties of Cd1-xCrxS diluted Magnetic Semiconductor (x=0.03125) in Zinc Blende (B3) phase. The calculations have been performed using Density functional theory as implemented in the Spanish Initiative for Electronic Simulations with Thousands of Atoms code using local density approximation as exchange-correlation (XC) potential. Calculated electronic band structures and magnetic properties of Cd1-xCrxS are discussed in terms of contribution of Cr 3d5 4s1, Cd 4d10 5s2, S 3s2 3p4 orbital’s. Study of band structures shows half-metallic ferromagnetic nature of Cd1-xCrxS. The calculated values of s-d exchange constant Nα and p-d exchange constant Nβ shows the magnetic nature of these compounds.

Spanish Initiative for Fully Automated Stowage on Roll-on/roll-off Operations

In the past decades, social development has motivated a notable growth on transportation necessities. In 2020, higher tendencies are expected, so transportation demand will grow about a 20%. Besides, one of the foundations of the UE's Green Policy initiative for freight is the transportation sea-to-ground through the so-called “Short sea shipping” or “Motorways of the sea”. Facing this scenario, it is needed the development of technologies and solutions which contribute to raise the profitability, flexibility and efficiency of marine transportation. This will lead to more competitive freight, so investing on such technologies is a guarantee of success. On this basis, within the framework of the Innterconecta 2013 programme, funded by the Spanish Ministry of Economy and Competitiveness through the Centre for Industrial Technological Development (CDTI), the project AUTOPORT is being developed, which objectives are here detailed. The main objective of the project is to develop the technologies needed for a fully automated stowage on roll-on/roll-off ships in order to improve the logistic flow, reduce stowage times and maximize the efficiency of the space occupation in hold. This will be accomplished by both the automation of logistic processes and terminal trucks. Automation of processes aims for obtaining a stowage plan which reduces to the minimum the obstructions between cargo and trucks in the process and also the imbalance of the hold, in order to allow easy and smooth load operations even in rough sea conditions. Automation of terminal trucks consist in the efficient use of localization, path planning and control for taking a specifically designated roll trailer and stowing it on the exact hold location pointed by the stowage plan, all without human intervention.

Study of gold nanostructures of various dimensions: Au NWs, Au nanosheets, Au nanocylinders

Using atomistic simulations, we study the impact of stretching on the structural evolution of 1D monatomic gold nanochains (MACs) undergoing elongation using SIESTA (Spanish Initiative for Electronic Simulation with Thousands of Atoms), the computational code based on DFT. Further we extend our work to the study of 2D gold nanosheets and 3D gold nanocylinders. Since the study of stretching of gold nanosheets and nanocylinders using DFT is computationally demanding, we will be using many body Gupta Potential.It will be seen that during the stretching of nanosheets different defects will arise while stretching of gold nanocylinders leads to gold monoatomic chain formation.

Electronic Properties of 6H Hexagonal SrMnO3

SrMnO3 ceramic was prepared by conventional high-temperature sintering method. Dielectric studies were performed within the temperature range 125–300 K at the frequency 10–400 kHz. The electronic properties of stoichiometric and oxygen defected SrMnO3 crystal in hexagonal 6H- P63/mmc symmetry at 0 K were calculated in ab initio procedure based on density functional theory using the Spanish Initiative for Electronic Simulations with Thousands of Atoms (SIESTA) code. The lattice parameters and density of states were obtained. The ideal 6H-SrMnO3 crystal has the band gap energy about 0.2–0.3 eV at 0 K. Contribution of an exchange-correlation energy into the total energy is about 32%, a magnetic moment about 3 µB.

First-Principles Study of Hydrogen Storage in Fe-Ti System

In this study, a first-principles investigation of hydrogen storage in the FeTi intermetallic is carried out. The structural and electronic changes due to hydrogen insertion into the FeTi intermetallic are determined using DFT and pseudo-potential calculations through the code SIESTA (Spanish Initiative for Electronic Simulation of Thousand of Atoms). The pseudopotentials are constructed using Troullier and Martins parametrization which describes correctly the ion-electron interactions. To define the real-space grid, necessary for numerical calculations of the electron density, detailed tests were performed in order to choose the appropriate basis set, the energy cutoff and the k-grid cutoff. The exchange-correlation potential is treated with the generalized gradient approximation (GGA). Lattice data, bonding properties and the density of states provide an explanation for the role played by hydrogen in the chemical bond with the Ti and Fe constituents.

Stability and electronic properties of Cd0.75Mn0.25S and Cd0.75Mn0.25Se in B3 phase

We studied the structural, elastic, spin-polarized electronic band structures and magnetic properties of the diluted magnetic semiconductor Cd1−x Mn x S and Cd1−x Mn x Se in zinc blende phase (B3) for x = 0.25 using ab initio method. The calculations were performed by using density functional theory as implemented in the Spanish Initiative for Electronic Simulations with Thousands of Atoms code using local density approximation. Calculated electronic band structures and magnetic properties of Cd1−x Mn x S are discussed in terms of contribution of Mn 3d 5 4s 2, Cd 4d 10 5s 2, S 3s 2 3p 4 orbitals. The total magnetic moment is found to be 5.00 µb for Cd1−x Mn x S and Cd1−x Mn x Se at x = 0.25. This value indicates that Mn atom adds no hole carrier to the perfect CdS crystal. We determine the spin-exchange splitting energies produced by Mn 3d states, s-d exchange constant N 0 α, and p-d exchange constant N 0 β. We found that Mn-doped systems are ferromagnetic. Calculated results are in good agreement with previous studies.

Effect of Dopant Concentration on Electronic and Magnetic Properties of Transition Metal-Doped ZrO2

Electronic and magnetic properties of the bulk monoclinic phase of pure and doped zirconia (ZrO2) are calculated. Calculations have been performed using density functional theory based Spanish Initiative for Electronic Simulations with Thousands of Atoms (SIESTA) code. We have considered substitutional doping of transition metals (TM) V, Cr, Mn and Fe in zirconia corresponding to concentrations ranging from 3.125 to 25 %. Our results show that Cr, Mn-, and Fe doped oxides are half-metallic and the half-metallicity remains intact on reducing the dopant concentrations. The total magnetic moment is mainly due to d states of TM atoms and small induced magnetic moment exists on other nonmagnetic atoms as well. Also as the oxygen vacancy influences the performance of oxidebased devices, therefore we model the influence of oxygen vacancy on the magnetic moments in pure and doped zirconia. Our results show that pure oxide system remains nonmagnetic even on the introduction of oxygen vacancy whereas magnetic moment values for TM doped oxide changes. In the presence of oxygen vacancy, the total magnetic moment of V-, Cr-, and Mn doped cell increases whereas it decreases for Fe doping. This shows that oxygen vacancy (V O) has a strong influence on the magnetic properties of the doped oxides. The results may be useful for further study on TM doped ZrO2 system.