Philippe F. Weck

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The structures of the only known minerals containing peroxide, namely studtite [(UO(2))O(2)(H(2)O)(4)] and metastudtite [(UO(2))O(2)(H(2)O)(2)], have been investigated using density functional theory. The structure of metastudtite crystallizing in the orthorhombic space group Pnma (Z = 4) is reported for the first time at the atomic level and the computed(More)
Citation Safavi-Naini, A. et al. " Microscopic model of electric-field-noise heating in ion traps. Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The MIT Faculty has made this article openly available. Please share how this access benefits(More)
Phases of the iron-oxygen binary system are significant to most scientific disciplines, directly affecting planetary evolution, life, and technology. Iron oxides have unique electronic properties and strongly interact with the environment, particularly through redox reactions. The iron-oxygen phase diagram therefore has been among the most thoroughly(More)
We report the structures and electronic properties of nine novel rare earth technetate pyrochlores with ideal stoichiometry Ln(2)Tc(2)O(7) (Ln = Ce-Pm, Gd, Tb, Ho, Tm, Lu) predicted within the framework of gradient-corrected density functional theory. The computed structures of Er(2)Tc(2)O(7), Dy(2)Tc(2)O(7), and Sm(2)Tc(2)O(7) also closely match available(More)
The structures and properties of layered technetium dichalcogenides TcX2 (X = S, Se, Te) have been investigated using density functional theory. The equilibrium structures of TcSe2 and TcTe2, adopting distorted Cd(OH)2-type unit cells similar to TcS2, are reported for the first time at the atomic level, along with their electronic properties. In contrast to(More)
In this work, we report total cross sections for the single electron capture process induced on DNA/RNA bases by high-energy protons. The calculations are performed within both the continuum distorted wave and the continuum distorted wave-eikonal initial state approximations. The biological targets are described within the framework of self-consistent(More)
We combine experimental observations with ab initio calculations to study the reversible hydrogenation of single-wall carbon nanotubes using high boiling polyamines as hydrogenation reagents. Our calculations characterize the nature of the adsorption bond and identify preferential adsorption geometries at different coverages. We find the barrier for(More)
We report the crystal structures of the novel technetium tetrahalides TcX(4) [X = F, I], as predicted from first-principles calculations. Isomorphous with TcCl(4) and TcBr(4) crystals, TcF(4) is orthorhombic with the centro-symmetric space group Pbca, while TcI(4) crystallizes in the monoclinic space group P2(1)/c. The structures,(More)
Quantum-mechanical calculations are reported for the Li+HF(v=0,1,j=0)-->H+LiF(v',j') bimolecular scattering process at low and ultralow temperatures. Calculations have been performed for zero total angular momentum using a recent high-accuracy potential-energy surface for the X2A' electronic ground state. For Li+HF(v=0,j=0), the reaction is dominated by(More)
Based on first-principles calculations, we propose a novel class of 3-D materials consisting of small diameter single-walled carbon nanotubes (SWCNTs) functionalized by organic ligands as potential hydrogen storage media. Specifically, we have carried out density functional theory calculations to determine the stable structures and properties of(More)