Ab initio GWquasiparticle calculation of small alkali-metal clusters

Quasiparticle energies of small alkali-metal clusters (Liₙ, Naₙ, Kₙ; $n=2,4,6,8)$ are evaluated from first principles by means of the GW approximation with the generalized plasmon-pole model. An all-electron mixed-basis approach, in which wave function is represented as a linear combination of both plane waves and atomic orbitals, is adopted in the calculation. Obtained quasiparticle energies (ionization potential and electron affinity) are in good agreement with available experimental data.