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. (Haubrich, Loffreda et al, CPL 2006)
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
Benzene
Phenyl + H

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

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

22. (Bocquet, Lesnard, Lorente, PRL 06)
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