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LYON permanent Team involved in MONET

LYON permanent Team involved in MONET. Marie-Laure Bocquet, CNRS Researcher, Lyon David Loffreda, CNRS Researcher,Lyon +External Collaborator: Nicolas Lorente, Professor IUF, Toulouse Special Thanks to Herve Lesnard, 3rd Year PhD. Outline. Introduction to periodic DFT approach (VASP code)

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LYON permanent Team involved in MONET

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  1. LYON permanent Team involved in MONET • Marie-Laure Bocquet, CNRS Researcher, Lyon • David Loffreda, CNRS Researcher,Lyon +External Collaborator: • Nicolas Lorente, Professor IUF, Toulouse Special Thanks to Herve Lesnard, 3rd Year PhD

  2. Outline Introduction to periodic DFT approach (VASP code) I. Classical outputs in our group II. New outputs in our group III. Projects

  3. Density Functional Theory (DFT):Kohn-Sham equations ‘The ‘orbital’ concept : one-electron wave function if V( r) periodic

  4. Various methods for solving Kohn-Sham equations

  5. The surface model… slabs! • surface = 3D metallic slab (supercell approach) • coverage = adlayer + superstructure

  6. Adsorption and surface energies • DFT: energy at T=0 K et P=0 atm Eads = energy gain due to adsorption surf = energy loss due to surface formation

  7. Bridging (T,P) gaps!… Atomistic thermodynamics • free Gibbs energy G(T,P) • Gas phase = large reservoir imposing its temperature and pressure on the adsorbed phase… …temperature effects on metal negligible

  8. I. Classical outputs in our group • STM simulations • Vibration Analysis • HREELS Spectra simulation • Reactive pathways

  9. STM simulations (Lorente) • Workhorse • Improvement: Matching procedure of DFT sample swith analytical exp. decaying s. =>Plot density contours at realistic distances.

  10. Ex: STM simulations of phenyl and benzyl species Structures Improved TH simulations

  11. Vibration Analysis: normal modes

  12. Ex: CH modes for phenyl and benzyl species on Cu(100) In and Out Decoupling Coupling

  13. IRAS and EELS intensity calculations • Infrared Reflection-Absorption Spectroscopy (IRAS) • Electron Energy Loss Spectroscopy (EELS) in Specular Geometry • Selection rules: vibrational modes giving rise to an oscillating • dynamic dipole moment along the surface • normal are active

  14. Ex: Structure Recognition - HREELS croton/Pt(111) (Haubrich, Loffreda et al, CPL 2006)

  15. Transition State Search(Henkelman & Jonsson) « Nudged-Elastic Band » (NEB) method • Set of n images linked with spring forces • ‘Nudged’ force acting on each i image:

  16. Ex: Successive Dehydrogenation on Cu(100)(Lesnard, Bocquet, Lorente, JACS in press 2007) TS structures Benzyl + 2H Phenyl + H Benzene

  17. II. New outputs in our group • STM-IETS simulations • Electrochemical phase diagram: water/Pd

  18. Elastic and Inelastic Electron Tunneling (Stipe, Rezaei, Ho,98)

  19. IETS: theoretical strategy (Lorente, Persson et al, PRL 00,01) Local density of one-electron states

  20. IETS: methodology (Lorente, Persson et al, PRL 00,01)  response to a vibration k: 4-step procedure finite difference

  21. Ex: IETS experiments (Lauhon & Ho, SS 2000 and Komeda et al, JCP 2004) Cu(100) Pulse 2.9 V C6H6 dis-C6H6 : benzyl

  22. Ex:IETS simulations (Bocquet, Lesnard, Lorente, PRL 06) Phenyl (-1H) Benzyl (-2H) dis-C6H6 Rule out experimental assigment

  23. The electrochemical approach (Filhol and Neurock, Angewandte 2006) Electrochemical energy

  24. Ex: water 1ML /Pd(111): charged interface! (Filhol&Bocquet, CPL 2007 in press) H-up / Pd(111) H-down / Pd(111) Pd disproportionation

  25. Ex: Charge control of oxygen buckling (Filhol&Bocquet, CPL 2007 in press)

  26. Monet Project: liquid+molecules/metal interface (Fradelos’s PhD project) Insertion of Large organic Molecules Image: Courtesy of JS Filhol Explicit water: multilayers

  27. Monet Project: graphene/Ru interface (Wang’s PhD project) STM/STS simulations STM image: J. Wintterlin’s group PRB 2007 in press Moiré pattern 11x11

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