. 2008 Jul 1;105(27):9157–9162. doi: 10.1073/pnas.0801001105

Table 1.

Experimentally determined band gaps for free gas-phase gold cluster anions from photoelectron spectroscopy vs. theoretical DFT values (PBE functional) for HOMO–LUMO gaps of passivated gold cluster compounds that correspond to 8, 34, and 58 conduction-electron shell closings

Shell closing	Experiment		Theory (this work)
Shell closing	Cluster	Gap, eV	Cluster compound	Gap, eV
8e (1S²1P⁶)			Au₁₁(PH₃)₇(SMe)₃	1.5
8e			Au₁₁(PH₃)₇Cl₃	2.1
8e			Au₁₃(PH₃)₁₀Cl₂³⁺^*	1.8
8e			Au₂₅(SMe)₁₈⁻^†	1.2
34e (8e + 1D¹⁰2S²1F¹⁴)	Au34^−‡§	1.0	Au₃₉Cl₆(PH₃)₁₄⁻	0.8
58e (34e + 2P⁶1G¹⁸)	Au58^−‡¶	0.6	Au₁₀₂(p-MBA)₄₄	0.5
58e			Au₁₀₂(SMe)₄₄	0.5^‖

*Ref. 16; the cationic charge is compensated by 3 non-coordinated PF₆⁻ anions in the experimental crystal structure.

^†Ref. 41.

^‡Ref. 32.

^§Ref. 34.

^¶Ref. 33.

^‖The calculation of the optical gap by a single-pole approximation in linear-response time-dependent DFT yields 0.55 eV for compound 2.