Interpretation of o binding-site preferences on close-packed group-viii metal surfaces

Physical Review B - Condensed Matter and Materials Physics

Volumn 59, Issue 3, 1999, Pages 2327-2331

  Feibelman, PeterJ ^a  

^a SANDIA NATIONAL LABORATORIES   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0001332531     PISSN: 10980121     EISSN: 1550235X     Source Type: Journal    
DOI: 10.1103/PhysRevB.59.2327     Document Type: Article

References (30)

1. The earlier paper, P. J. Feibelman, Phys. Rev. B 56, 10 532 (1997), offered an explanation of why O prefers the fcc site on Pt(111), but not why it chooses an hcp site instead, on Ru(0001).
2. N. Materer, U. Starke, A. Barbieri, R. Döll, K. Heinz, M. A. Van Hove, and G. A. Somorjai, Surf. Sci. 325, 207 (1995).
3. M. Lindroos, H. Pfnòr, G. Held, and D. Menzel, Surf. Sci. 222, 451 (1989).
4. For a compilation, see P. R. Watson, M. A. van Hove, and K. Hermann, Atlas of Surface Structures (American Institute of Physics, Woodbury, NY, 1994), Vol. 1A.
5. K. Fukui, Science 218, 747 (1982).
6. Alternately of near-Fermi-level local-density-of-states weight; see P. J. Feibelman and D. R. Hamann, Surf. Sci. 149, 48 (1985);
7. P. J. FeibelmanD. R. HamannPhys. Rev. Lett. 52, 61 (1984).
8. See The Theory of the Inhomogeneous Electron Gas, edited by S. Lundqvist and N. H. March (Plenum, New York, 1983);
9. also, W. E. Pickett, Comput. Phys. Rep. 9, 115 (1989).
10. As discussed in detail below (see Ref. 18), the energy difference I report in Table II, for (Formula presented) is larger than the value of 0.43 eV published by C. Stampfl and M. Scheffler,
11. Phys. Rev. B 54, 2868 (1996).
12. The idea of viewing strong chemisorption as the rebonding of a complex to an indented surface was introduced almost three decades ago, as a limit of an empirical tight-binding approach to surface energetics. See, e.g., T. B. Grimley, in Molecular Processes on Surfaces, edited by E. Drauglis, R. D. Gretz, and R. I. Jaffee (McGraw-Hill, New York, 1969), p. 299;
13. J. R. Schrieffer and R. Gomer, Surf. Sci. 25, 315 (1971);
14. Surf. Sci.R. H. Paulson and J. R. Schrieffer, 48, 329 (1975). The present case is the first, to my knowledge, where it emerges naturally from the results of first-principles calculations.
15. G. Kresse and J. Hafner, Phys. Rev. B 47, 558 (1993);
16. Phys. Rev. BG. KresseJ. Hafner49, 14 251 (1994).
17. G. Kresse and J. Furthmüller, Comput. Mater. Sci. 6, 15 (1996).
18. G. Kresse and J. Furthmüller, Phys. Rev. B 54, 11 169 (1996).
19. D. M. Ceperley and B. J. Alder, Phys. Rev. Lett. 45, 566 (1980),
20. as parametrized by J. Perdew and A. Zunger, Phys. Rev. B 23, 5048 (1981).
21. J. P. Perdew, in Electronic Structure of Solids ’91, edited by P. Ziesche and H. Eschrig (Akademie Verlag, Berlin, 1991);J. P. Perdew and Y. Wang (unpublished). The (Formula presented)implementation of the GGA is fully self-consistent, including the incorporation of gradient corrections to the exchange-correlation potential in the pseudopotentials.
22. For LDA Ru, (Formula presented) and (Formula presented) for GGA Ru, (Formula presented) and (Formula presented) and for LDA Pt, (Formula presented) Experimental room-temperature lattice constants for comparison are (Formula presented) and (Formula presented) for Ru and (Formula presented) for Pt.
23. M. Methfessel and A. T. Paxton, Phys. Rev. B 40, 3616 (1989).
24. H. Pfnür, G. Held, M. Lindroos, and D. Menzel, Surf. Sci. 220, 43 (1989).
25. As noted in Ref. 8, the (Formula presented) site-preference energies for (Formula presented) 0.61 eV (LDA), and 0.57 eV (GGA) are larger than the GGA value, 0.43 eV, reported by Stampfl and Scheffler (SS).To be certain that the difference does not reside in the use of the ultrasoft potentials, nor in basis convergence, I repeated the LDA calculations for O/Ru using QUEST[M. P. Sears, P. A. Schultz, and P. J. Feibelman (unpublished)], a local basis electronic-structure code that represents electron-core interactions via Hamann-type [D. R. Hamann, Phys. Rev. B 40, 2980 (1989)], semilocal pseudopotentials. The outcome is a preference of 0.66 eV for the hcp site, in reasonable agreement with the (Formula presented) result.For the qualitative discussion below, it is the sign rather than the magnitude of the preference energy that is important. But ultimately it would be useful to know the source of the quantitative difference from SS’s result. For reference, the Ru lattice parameters in the QUEST calculation are (Formula presented) and (Formula presented) in good agreement with the (Formula presented) values, (Formula presented) and (Formula presented)
26. It should be borne in mind that error bars in LEED analyses do not provide any information concerning the potential systematic error level in applying an approximate scattering theory to extract geometry from electron scattering data. Nor is the error in the usual R-factor analysis statistical noise. Therefore there is no clear way to add errors quoted for different structural parameters. I obtained the error values in Tables IIIIVV by computing maximum and minimum possible interatom distances, given the error bars quoted in Refs. 2 and 3.
27. Ru-Ru bond length changes, quoted in Sec. VI A of Ref. 1, for O/Ru were calculated relative to ideal, i.e., to unrelaxed, clean Ru(0001). Thus, it is not true that “Of the three bonds between each Ru atom adjacent to an O, and its neighbors in the second layer, LEED (i.e., Ref. 3) says that one is stretched 2.9% relative to the clean surface, but the other two are 2.4% contracted.” With Ru(0001)’s outer-layer relaxation taken into account, one is stretched about 5% and the others are virtually unchanged, as reported in Table V.
28. S. Papadia, B. Piveteau, D. Spanjaard, and M. C. Desjonquères, Phys. Rev. B 54, 14 720 (1996);
29. Phys. Rev. BB. Piveteau, D. Spanjaard, and M. C. Desjonquères, 46, 7121 (1992) attribute metal-atom adsorption-site preferences on d-band metals to band filling.
30. V. L. Moruzzi, J. F. Janak, and A. R. Williams, Calculated Electronic Properties of Metals (Pergamon, New York, 1978).