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exercises:2014_ethz_mmm:surface_au

Calculation of surface energies of Au

Take the above table as reference for the orders of magnitude of surface energies. You can download the commented inputs by downloading from the wiki: exercise_3.2.zip) the necessary files for computing the surface energies of all 3 high symmetry faces of gold. In principle all reconstructed phases should be with a lower surface energy, but this EAM potential fails for some of them. The input files are:

  1. 100_bulk.inp for determining the energy per atom in the bulk
  2. 100_unr.inp for the bulk termination (100)
  3. 100_rec.inp for the hexagonally reconstructed (100)
  4. 110_unr.inp for the (110) bulk termination
  5. 110_rec.inp for the (2×1) reconstruction
  6. 111.inp for the unreconstructed (111).

The compute_surf scripts give an idea how to compute the surface energies. Assignments:

  1. Mark surface energies and relaxations of the first 2-3 top layers (use vmd or editor)
  2. Try to color the surfaces in vmd in a way that makes the height evident (ask the assistant) and produce snapshots (render)
  3. Comment on the (2×1) reconstruction: what do you see?
  4. Plot the same, but adding periodic images in vmd: remember pbc set { a b c 90 90 90 }.

Hint: you can save a configuration file in vmd and reuse it for a new sample! Ask the assistant!

exercises/2014_ethz_mmm/surface_au.txt · Last modified: 2014/10/15 15:28 by oschuett