Quasiparticle effects and optical absorption in small fullerenelike GaP clusters

Quasiparticle corrections to the electronic energies have been calculated for small GaP fullerenes, a class of nanoscaled materials recently predicted to be stable. These clusters have been also characterized by us for their optical absorption spectra using time-dependent density functional theory. The comparison between single-particle and optical absorption spectra supports the evidence of strong excitonic effects with bonding energy up to 3.5 eV. The quasiparticle corrected highest-occupied-molecular-orbital-lowest-unoccupied-molecular-orbital energy gaps confirm the high stability predicted for such molecules using ground-state computational schemes. The present results will be useful to identify the successful synthesis of such systems via optical absorption and quasiparticle spectra.