Tight Binding Methods for Metallic Systems - Metallic Systems: A Quantum Chemist's Perspective - page 244

Au 3 Au 4 Au 5 Au 6 Au 7 Au 8

(1,2)(a-e)

(1)(a) (a,b) (2)(c,d) (1,2)(a,d) (a-e) (1,2)(a-e) (1)(e) (2)(a-c) (1, 2)(a-e)

Au 9 Au 10 Au 11 Au 12 Au 13

(1,2)(a,b) (1)(b) (2) (1,2)(b) (1) (b) (2)(c) (1) (b,c) (2)

Au 14 Au 15 Au 16 Au 17 Au 18

(b,c)

(1) (2) (1)(c) (2) (1)(c) (2) (1)(f) (2) (1)(f)

Au 19 Au 20

(1)(g) (2) (1)(f) (c) (2) (1)(c) (1) (2)

(b) DFT [30].
(c) DFT [36].
(d) DFT [37].

(e) DFT [38].
(f) DFT [39].
(g) DFT [19].

(1) Corrected tight-binding (this work).
(2) NRL-tight-binding [9].
(a) DFT [18].

FIGURE 8.2 Lowest. energy. neutral. gold. cluster. structures,. ranging. in. size. from. 3. to. 20.
atoms,.obtained.with.the.perturbatively.corrected.TB.method..The.results.are.compared.with.
DFT.and.NRL-TB.calculations.

2.5

2

1.5

1

5 10 15 20

Number of atoms

FIGURE 8.3 Binding.energy.per.atom.corresponding.to.the.lowest.energy.conigurations.
of.neutral.gold.clusters.of.different.sizes.

changes. due. to. orbital. rehybridization. are. observed.. The. perturbatively. corrected.
NRL-TB.geometries. compare.very. well. with.those. reported.in.recent.DFT. global.
optimization.calculations.on.gold.neutral.clusters.[55]..For.sizes.such.as. n .=.3,.4,.and.
7,.quasi-degenerate.global.minima.are.predicted.by.this.TB,.a.situation.that.has.been.
also.observed.in.some.DFT.calculations.[45,46,60,61].