Collective jumps of a Pt adatom on fcc-Pt (001): Nudged Elastic Band Calculation: Difference between revisions

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Description: calculate the energy barrier for the self-diffusion (of a Pt-adatom) on Pt (001): The most stable adsorption site of the adatom is the hollow (h) position. Simple models of the diffusion of the adatom from h to the neighboring h site include two diffusion paths: hollow-top-hollow (hth, eg along [1-10]) or hollow-bridge-hollow (hbh, eg along [100]). A collective jump mechanism involving 2 Pt atoms diffusing along [1-10] is proposed to be the diffusion mechanism with the lowest energy barrier .
Description: calculate the energy barrier for the self-diffusion (of a Pt-adatom) on Pt (001): The most stable adsorption site of the adatom is the hollow (h) position. Simple models of the diffusion of the adatom from h to the neighboring h site include two diffusion paths: hollow-top-hollow (hth, eg along [1-10]) or hollow-bridge-hollow (hbh, eg along [100]). A collective jump mechanism involving 2 Pt atoms diffusing along [1-10] is proposed to be the diffusion mechanism with the lowest energy barrier <ref name="kellog:prl64:3143"/>
 
The calculation of the barrier heights involves the following steps:
 
1. calculation of the bulk a<sub>0</sub> of Pt for the chosen functional
 
2. a clean Pt (001) surface, with a 2D supercell of -at minimum- (2x2) reconstruction
 
3. the energies of the surface including the Pt-adatom in h, b, and t position
 
4. a Nudged Elastic Band (NEB) calculation <ref name="NEB"/> for the proposed collective jump mechanism
 
steps 1-3 are straightforward, therefore only the files and the procedure for the NEB calculation are given here:
 
1. consider how many intermediate geometries (N) should be chosen between the initial and the final state of the jump
in INCAR, this corresponds to the tag
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
== References ==
<references>
<ref name="kellog:prl64:3143"> G.L.Kellogg and Peter J.Feibelman, Phys. Rev. Lett. <b>64</b> (26), 3143 (1990) </ref>
<ref name="NEB">G. Mills, H. Jonsson and G. K. Schenter, Surface Science, <b>324</b>, 305 (1995); H. Jonsson, G. Mills and K. W. Jacobsen,
`Nudged Elastic Band Method for Finding Minimum Energy Paths of Transitions',
in `Classical and Quantum Dynamics in Condensed Phase Simulations', ed. B. J. Berne, G. Ciccotti and D. F. Coker (World Scientific, 1998) </ref>

Revision as of 13:33, 8 June 2012

Description: calculate the energy barrier for the self-diffusion (of a Pt-adatom) on Pt (001): The most stable adsorption site of the adatom is the hollow (h) position. Simple models of the diffusion of the adatom from h to the neighboring h site include two diffusion paths: hollow-top-hollow (hth, eg along [1-10]) or hollow-bridge-hollow (hbh, eg along [100]). A collective jump mechanism involving 2 Pt atoms diffusing along [1-10] is proposed to be the diffusion mechanism with the lowest energy barrier [1]

The calculation of the barrier heights involves the following steps:

1. calculation of the bulk a0 of Pt for the chosen functional

2. a clean Pt (001) surface, with a 2D supercell of -at minimum- (2x2) reconstruction

3. the energies of the surface including the Pt-adatom in h, b, and t position

4. a Nudged Elastic Band (NEB) calculation [2] for the proposed collective jump mechanism

steps 1-3 are straightforward, therefore only the files and the procedure for the NEB calculation are given here:

1. consider how many intermediate geometries (N) should be chosen between the initial and the final state of the jump in INCAR, this corresponds to the tag











References

<references> [1] [2]

  1. a b G.L.Kellogg and Peter J.Feibelman, Phys. Rev. Lett. 64 (26), 3143 (1990)
  2. a b G. Mills, H. Jonsson and G. K. Schenter, Surface Science, 324, 305 (1995); H. Jonsson, G. Mills and K. W. Jacobsen, `Nudged Elastic Band Method for Finding Minimum Energy Paths of Transitions', in `Classical and Quantum Dynamics in Condensed Phase Simulations', ed. B. J. Berne, G. Ciccotti and D. F. Coker (World Scientific, 1998)