Search Results - (Author, Cooperation:R. Car)
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1Latest Papers from Table of Contents or Articles in PressJ. C. Palmer ; F. Martelli ; Y. Liu ; R. Car ; A. Z. Panagiotopoulos ; P. G. Debenedetti
Nature Publishing Group (NPG)
Published 2016Staff ViewPublication Date: 2016-03-11Publisher: Nature Publishing Group (NPG)Print ISSN: 0028-0836Electronic ISSN: 1476-4687Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsKeywords: *Models, Molecular ; Water/*chemistryPublished by: -
2Latest Papers from Table of Contents or Articles in PressJ. C. Palmer ; F. Martelli ; Y. Liu ; R. Car ; A. Z. Panagiotopoulos ; P. G. Debenedetti
Nature Publishing Group (NPG)
Published 2014Staff ViewPublication Date: 2014-06-20Publisher: Nature Publishing Group (NPG)Print ISSN: 0028-0836Electronic ISSN: 1476-4687Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsKeywords: *Models, Molecular ; Temperature ; Thermodynamics ; Water/*chemistryPublished by: -
3Articles: DFG German National LicensesHohl, D. ; Jones, R. O. ; Car, R. ; Parrinello, M.
College Park, Md. : American Institute of Physics (AIP)
Published 1988Staff ViewISSN: 1089-7690Source: AIP Digital ArchiveTopics: PhysicsChemistry and PharmacologyNotes: The ground state geometries of sulfur clusters S2 to S13 have been calculated using a parameter-free density functional (DF) method, combined with molecular dynamics (MD) and simulated annealing techniques. The results are in good agreement with available experimental data, and should provide reliable predictions where detailed measurements are lacking (n=3,4,5,9). The bonding trends are discussed in detail. The MD-DF approach is particularly valuable in larger clusters, where there are many local energy minima with comparable energies.Type of Medium: Electronic ResourceURL: -
4Articles: DFG German National LicensesLaasonen, K. ; Sprik, M. ; Parrinello, M. ; Car, R.
College Park, Md. : American Institute of Physics (AIP)
Published 1993Staff ViewISSN: 1089-7690Source: AIP Digital ArchiveTopics: PhysicsChemistry and PharmacologyNotes: An ab initio molecular dynamics simulation of liquid water has been performed using density functional theory in the Kohn–Sham formulation and a plane wave basis set to determine the electronic structure and the forces at each time step. For an accurate description of the hydrogen bonding in the liquid, it was necessary to extend the exchange functional with a term that depends on the gradient of the electron density. A further important technical detail is that supersoft pseudopotentials were used to treat the valence orbitals of the oxygen atoms in a plane wave expansion. The structural and dynamical properties of the liquid were found to be in good agreement with experiment. The ab initio molecular dynamics also yields information on the electronic structure. The electronic feature of special interest is the lowest unoccupied molecular orbital (LUMO) of the liquid which is the state occupied by a thermalized excess electron in the conductive state. The main result of calculating the liquid LUMO is that it is a delocalized state distributed over interstitial space between the molecules with a significant admixture of the σ* orbitals of the individual water molecules.Type of Medium: Electronic ResourceURL: -
5Articles: DFG German National LicensesBlase, X. ; Charlier, J.-C. ; De Vita, A. ; Car, R.
Woodbury, NY : American Institute of Physics (AIP)
Published 1997Staff ViewISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: The stability and electronic properties of composite BxCyNznanotube heterojunctions were studied using both ab initio and semi-empirical approaches. C/BN and BC2N/BN superlattices or isolated junctions were investigated as specific examples of the wide variety of electronic devices that can be realized using such nanotubes. The characteristics of these junctions are predicted to be largely independent of the radius, helicity, multiplicity, or degree of perfection of the constituting nanotubes. © 1997 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
6Articles: DFG German National LicensesKrishnamurthy, R. ; Yoon, Y.-G. ; Srolovitz, D. J. ; Car, R.
Oxford, UK : Blackwell Publishing Ltd
Published 2004Staff ViewISSN: 1551-2916Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision MechanicsPhysicsNotes: We present a multiscale modeling approach to study oxygen diffusion in cubic yttria-stabilized zirconia. In this approach, we employ density functional theory methods to calculate activation energies for oxygen migration in different cation environments. These are used in a kinetic Monte Carlo framework to calculate long-time oxygen diffusivities. Simulation results show that the oxygen diffusivity attains a maximum value at around 0.1 mole fraction yttria. This variation in the oxygen diffusivity with yttria mole fraction and the calculated values for the diffusivity agree well with experiment. The competing effects of increased oxygen vacancy concentration and increasing activation energy and correlation effects for oxygen diffusion with increasing yttria mole fraction are responsible for the observed dopant content dependence of the oxygen diffusivity. We provide a detailed analysis of cation-dopant-induced correlation effects in support of the above explanation.Type of Medium: Electronic ResourceURL: -
7Articles: DFG German National LicensesKrishnamurthy, R. ; Srolovitz, D. J. ; Kudin, K. N. ; Car, R.
Oxford, UK : Blackwell Science Inc
Published 2005Staff ViewISSN: 1551-2916Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision MechanicsPhysicsNotes: The effects of lanthanide co-dopants on oxygen diffusion in yttria-stabilized zirconia (YSZ) are studied using a combined first principles density functional theory (DFT)/kinetic Monte Carlo (kMC) modeling approach. DFT methods are used to calculate barrier energies for oxygen migration in different local cation environments, which are then input into kMC simulations to obtain long-time oxygen diffusivities and activation energies. Simulation results show a substantial increase in the maximum value of the oxygen diffusivity upon co-doping and in the dopant content at which this value is obtained for Lu-co-doped YSZ; while relatively little change is seen for Gd-co-doped YSZ. Examination of the DFT barrier energies reveals a linear scaling of barrier heights with the size of cations at the diffusion transition state. Using this strong correlation, oxygen diffusivity is examined in YSZ co-doped with several lanthanide elements. The oxygen diffusivity decreases with dopant atomic number (and decreasing dopant ion size) for co-dopants smaller than Y, and changes relatively little when Y is replaced by co-dopants larger than it. These results are broadly consistent with experiment, and are explained in terms of cation-dopant and vacancy concentration-dependent correlation effects, with the aid of a simple analytical model.Type of Medium: Electronic ResourceURL: -
8Articles: DFG German National LicensesStaff View
ISSN: 0921-4526Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: PhysicsType of Medium: Electronic ResourceURL: -
9Articles: DFG German National LicensesStaff View
ISSN: 0021-9991Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: Computer SciencePhysicsType of Medium: Electronic ResourceURL: -
10Articles: DFG German National LicensesStaff View
ISSN: 0038-1098Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: PhysicsType of Medium: Electronic ResourceURL: -
11Articles: DFG German National LicensesStaff View
ISSN: 0038-1101Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: Electrical Engineering, Measurement and Control TechnologyPhysicsType of Medium: Electronic ResourceURL: -
12Articles: DFG German National LicensesStaff View
ISSN: 0039-6028Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: PhysicsType of Medium: Electronic ResourceURL: -
13Articles: DFG German National LicensesStaff View
ISSN: 0039-6028Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: PhysicsType of Medium: Electronic ResourceURL: -
14Articles: DFG German National LicensesStaff View
ISSN: 0039-6028Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: PhysicsType of Medium: Electronic ResourceURL: -
15Articles: DFG German National LicensesStaff View
ISSN: 0039-6028Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: PhysicsType of Medium: Electronic ResourceURL: -
16Articles: DFG German National LicensesGhidini, B. ; Muller, K. ; Eades, J. ; French, B. ; Mandelli, L. ; Navach, F. ; Picciarelli, V. ; Bailey, J. ; Edwards, D.N. ; Minelli, G. ; Smith, I.L. ; Fry, J. ; Edwards, M. ; D'Angelo, P. ; Car, R. ; Grabar, S.
Amsterdam : ElsevierStaff ViewISSN: 0029-554XSource: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: Energy, Environment Protection, Nuclear Power EngineeringPhysicsType of Medium: Electronic ResourceURL: -
17Articles: DFG German National LicensesStaff View
ISSN: 0039-6028Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: PhysicsType of Medium: Electronic ResourceURL: -
18Articles: DFG German National LicensesStaff View
ISSN: 0038-1098Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: PhysicsType of Medium: Electronic ResourceURL: -
19Articles: DFG German National LicensesStaff View
ISSN: 0038-1098Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: PhysicsType of Medium: Electronic ResourceURL: -
20Articles: DFG German National LicensesStaff View
ISSN: 0038-1098Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: PhysicsType of Medium: Electronic ResourceURL: