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Alfredo Pasquarello

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Related publications (154)

Page 4 of 8

Structural and electronic properties of oxygen vacancies in monoclinic HfO2

Alfredo Pasquarello, Peter Broqvist

We study structural and electronic properties of the oxygen vacancy in monoclinic HfO 2 for five different charge states. We use a hybrid density functional to accurately reproduce the experimental band gap. To compare with measured defect levels, we deter ...

2007

Minimum energy path and atomistic mechanism of the elementary step in oxygen diffusion in silicon: A density-functional study

Alfredo Pasquarello, Jan Felix Binder

Using a density-functional scheme, we study the migration of a single O atom in a (110) plane between two adjacent bond-center sites in bulk Si. The minimum energy migration path is found through the nudged elastic band method within a generalized gradient ...

American Physical Society2014

Low-strain interface models for epitaxial graphene on SiC(0001)

Alfredo Pasquarello, Gabriele Sclauzero

A set of low-strain commensurate interface structures for epitaxial graphene on SiC(0001) are obtained by combining rotated graphene supercells with m x m or m root 3 x m root 3R30 degrees SiC cells. For two among the interfaces with lowest strain, corresp ...

Elsevier2012

Modeling of atomic-scale processes during silicon oxidation: charge state of the O2 molecule

Alfredo Pasquarello, Audrius Alkauskas

We discuss the ab initio modeling of several processes occurring during silicon oxidation with a particular emphasis on the charge state of the diffusing oxygen molecule. For values of the electron chemical potential falling in the range of the silicon ban ...

2007

Comparison of vacancy and antisite defects in GaAs and InGaAs through hybrid functionals

Alfredo Pasquarello, Hannu-Pekka Komsa

The formation energies and charge transition levels of vacancy and antisite defects in GaAs and In0.5Ga0.5As are calculated through hybrid density functionals. In As-rich conditions, the As antisite is the most stable defect in both GaAs and InGaAs, except ...

2012

Electronic and structural characterization of barrier-type amorphous aluminium oxide

Alfredo Pasquarello, Francesco Ambrosio, Claudia Cancellieri

The structural, electronic, and dielectric properties of barrier -type anodic Al oxides prepared with various thicknesses have been investigated. The planar and cross morphologies as well as the surface charge distribution were investigated as a function o ...

Elsevier2017

Picture of the wet electron: a localized transient state in liquid water

Alfredo Pasquarello, Francesco Ambrosio, Michele Pizzochero

A transient state of the excess electron in liquid water preceding the development of the solvation shell, the so-called wet electron, has been invoked to explain spectroscopic observations, but its binding energy and atomic structure have remained highly ...

2019

Vibrational properties of vitreous GeSe2 with the Becke-Lee-Yang-Parr density functional

Alfredo Pasquarello, Luigi Giacomazzi

The vibrational properties of vitreous GeSe2 are studied within the Becke-Lee-Yang-Parr (BLYP) generalized gradient approximation to density functional theory. For this purpose, we consider two models. The first one is derived from a chemically ordered net ...

2011

On the Electronic and Optical Properties of Metal-Organic Frameworks: Case Study of MIL-125 and MIL-125-NH2

Berend Smit, Alfredo Pasquarello, Kyriakos Stylianou, Francesco Ambrosio, Gloria Capano, Stavroula Kampouri

The photo-active MIL-125 and MIL-125-NH2 metal-organic frameworks (MOFs), despite having a very similar crystalline structure, exhibit different optical behaviors. Luminescence in MIL-125 decays in about 1 ns, while for its amino counterpart, the lifetime ...

2020

Absolute deformation potentials of two-dimensional materials

Alfredo Pasquarello, Julia Anna Wiktor

We present ab initio calculations of uniaxial absolute deformation potentials of the valence and the conduction bands in monolayer MoS2, MoSe2, WS2, WSe2, h-BN, and phosphorene. Calculations are performed using both semilocal and hybrid functionals. The ab ...

Amer Physical Soc2016

2023 Roadmap on molecular modelling of electrochemical energy materials

Alfredo Pasquarello, Chunmin Zhang, Assil Bouzid

New materials for electrochemical energy storage and conversion are the key to the electrification and sustainable development of our modern societies. Molecular modelling based on the principles of quantum mechanics and statistical mechanics as well as em ...

Iop Publishing Ltd2023

Infrared spectra of jennite and tobermorite from first-principles

Alfredo Pasquarello, Gabriele Sclauzero

The infrared absorption spectra of jennite, tobermorite 14 angstrom, anomalous tobermorite 11 angstrom, and normal tobermorite 11 angstrom are simulated within a density-functional-theory scheme. The atomic coordinates and the cell parameters are optimized ...

Pergamon-Elsevier Science Ltd2014

Carbon rehybridization at the graphene/SiC(0001) interface: Effect on stability and atomic-scale corrugation

Alfredo Pasquarello, Gabriele Sclauzero

We address the energetic stability of the graphene/SiC(0001) interface and the associated binding mechanism by studying a series of low-strain commensurate interface structures within a density functional scheme. Among the structures with negligible strain ...

2012

Exploring Defects in Semiconductor Materials Through Constant Fermi Level Ab-Initio Molecular Dynamics

Alfredo Pasquarello

We focus on the determination of point defects in semiconductor materials through constant-Fermi-level ab initio molecular dynamics and demonstrate that this technique can be used as a computer-based tool to reveal and control relevant defects in semicondu ...

Springer2020

First-principles investigation of the relation between structural and NMR parameters in vitreous GeO2

Alfredo Pasquarello

NMR parameters of Ge-73 and O-17 in vitreous GeO2 and quartz GeO2, including the isotropic shifts, the quadrupole coupling constants C-Q, and the electric-field-gradient asymmetry parameters., are determined through density functional calculations. Clear c ...

2010

Structural, Dynamical, and Electronic Properties of Liquid Water: A Hybrid Functional Study

Alfredo Pasquarello, Francesco Ambrosio, Giacomo Francesco Leonardo Miceli

We study structural, dynamical, and electronic properties of liquid water through ab initio molecular dynamics (MD) simulations based on a hybrid functional which includes nonlocal van der Waals (vdW) interactions. The water dimer, the water hexamer, and t ...

Amer Chemical Soc2016

Adjustable potential probes for band-gap predictions of extended systems through nonempirical hybrid functionals

Alfredo Pasquarello, Igor Reshetnyak, Thomas Bischoff

We describe a nonempirical procedure for achieving accurate band gaps of extended systems through the insertion of suitably defined potential probes. By enforcing Koopmans' condition on the resulting localized electronic states, we determine the optimal fr ...

2019

Atomistic model of the 4H(0001)SiC-SiO2 interface: structural and electronic properties

Alfredo Pasquarello, Fabien Devynck, Feliciano Giustino

Through the sequential use of classical molecular dynamics and first-principles relaxation methods, we generate an abrupt model interface for the 4H(0001)SiC-SiO2 interface showing regular structural parameters without any coordination defect. The valence ...

2007

Evaluation of Photocatalysts for Water Splitting through Combined Analysis of Surface Coverage and Energy-Level Alignment

Alfredo Pasquarello, Francesco Ambrosio, Zhendong Guo

To examine whether suitable conditions occur for the water splitting reaction at their interfaces with liquid water, we determine the pH-dependent surface coverage for a series of semiconductors, including GaAs, GaP, GaN, CdS, ZnO, SnO2, and rutile and ana ...

2020

Defect levels through hybrid density functionals: Insights and applications

Alfredo Pasquarello, Peter Broqvist, Audrius Alkauskas

Hybrid density functional calculations applied to defect charge transition levels are explored in the attempt to overcome the band-gap problem of semilocal density functionals. Charge transition levels of a large set of point defects calculated with semilo ...

2011