Computation of electron energy loss spectra by an iterative method

Peter Koval (1, 2) , Mathias Per Ljungberg (2) , Dietrich Foerster (3) , Daniel Sánchez-Portal (2, 1)

1 CFM - Centro de Fisica de Materiales
2 Donostia International Physics Center - DIPC (SPAIN)
3 LOMA - Laboratoire Ondes et Matière d'Aquitaine

A method is presented to compute the dielectric function for extended systems using linear response time dependent density functional theory. Localized basis functions with finite support are used to expand both eigenstates and response functions. The electron energy loss function is directly obtained by an iterative Krylov subspace method. We apply our method to graphene and silicon and compare it to plane wave based approaches. Finally, we compute electron energy loss spectrum of C 60 crystal to demonstrate the merits of the method for molecular crystals, where it will be most competitive.

Mots clés: Product basis set; Localized functions; Extended systems; Iterative TDDFT

Domaines: Physique mathématique [math-ph]

Peter Koval, Mathias Per Ljungberg, Dietrich Foerster, Daniel Sánchez-Portal. Computation of electron energy loss spectra by an iterative method. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2015, 354, pp.216-219. ⟨10.1016/j.nimb.2014.11.080⟩. ⟨hal-01174984⟩