Concept

Méthode quantique semi-empirique

Publications associées (153)

Dominant phonon wave vectors and strain-induced splitting of the 2D Raman mode of graphene

The dominant phonon wave vectors q* probed by the 2D Raman mode of pristine and uniaxially strained graphene are determined via a combination of ab initio calculations and a full two-dimensional integration of the transition matrix. We show that q* are hig ...

2012

Complete C-13 NMR Chemical Shifts Assignment for Cholesterol Crystals by Combined CP-MAS Spectral Editing and ab Initio GIPAW Calculations with Dispersion Forces

We report here the first fully oh initio determination of C-13 NMR spectra for several crystal structures of cholesterol, observed in various biomaterials. We combine Gauge-Including Projector Augmented Waves (GIPAW) calculations at relaxed structures, ful ...

2012

Disentanglement of Surface and Bulk Rashba Spin Splittings in Noncentrosymmetric BiTeI

Jan Hugo Dil, Thorsten Schmitt, Vladimir N. Strocov, Stefan Peter Muff

BiTeI has a layered and noncentrosymmetric structure where strong spin-orbit interaction leads to a giant Rashba spin splitting in the bulk bands. We present direct measurements of the bulk band structure obtained with soft x-ray angle-resolved photoemissi ...

2012

Ultrafast excited-state dynamics of strongly coupled porphyrin/core-substituted-naphthalenediimide dyads

Natalie Renuka Banerji, Eric Vauthey

The photophysics and excited-state dynamics of two dyads consisting of either a free-base or a zinc-tetraphenylporphyrin linked through a rigid bridge to a core-substituted naphthalenediimide (NDI) have been investigated by femtosecond-resolved spectroscop ...

2011

Mixed Quantum Mechanical/Molecular Mechanical (QM/MM) simulations of Adiabatic and Nonadiabatic Ultrafast Phenomena

Ursula Röthlisberger, Ivano Tavernelli, Basile Curchod, Thomas James Penfold, Pablo Campomanes Ramos, Marilisa Neri, Stefano Vanni, Andrey Laktionov

A thorough theoretical description of ultrafast phenomena that occur in complex systems constitutes a formidable challenge. It not only necessitates the use of quantum mechanical methods that can describe ground and possibly even electronically excited sta ...

Schweizerische Chemische Gesellschaft2011

Experimental charge density of LiBD4 from maximum entropy method

Philippe Mauron

We report on maximum entropy method study of the experimental atomic and ionic charges of LiBD4 in its low-temperature orthorhombic phase. Synchrotron radiation x-ray powder diffraction data, neutron powder diffraction data, and density functional calculat ...

2011

Beating the Efficiency of Both Quantum and Classical Simulations with a Semiclassical Method

Jiri Vanicek, Cesare Mollica

While rigorous quantum dynamical simulations of many-body systems are extremely difficult (or impossible) due to exponential scaling with dimensionality, the corresponding classical simulations ignore quantum effects. Semiclassical methods are generally mo ...

American Physical Society2011

Band-edge problem in the theoretical determination of defect energy levels: The O vacancy in ZnO as a benchmark case

Alfredo Pasquarello, Audrius Alkauskas

Calculations of formation energies and charge transition levels of defects routinely rely on density functional theory (DFT) for describing the electronic structure. Since bulk band gaps of semiconductors and insulators are not well described in semilocal ...

2011

Studies of mode I delamination in monotonic and fatigue loading using FBG wavelength multiplexing and numerical analysis

John Botsis, Joël Cugnoni, Samuel Stutz

Bridging by intact fibers in composite materials is one of the most important toughening mechanisms. However, a direct experimental assessment of its contribution is not easy to achieve. In this work a semi-experimental method is proposed to quantify its c ...

2011

Effect of adsorbed H atoms on magnetism in monoatomic Fe wires at Ir(100)

Zeljko Sljivancanin, Alfonso Baldereschi

By means of ab initio calculations based on density-functional theory we demonstrate that magnetism in monoatomic Fe wires deposited on nanostructured Ir(100) surface can be tuned by their functionalization with hydrogen. The pristine monoatomic Fe wires d ...

2010

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