Ball Pivoting Algorithm and discrete gaussian curvature: A direct way to curved nanographene circularly polarized luminescence spectral simulation

Abstract

Theoretical innovations for constructing robust computational protocols are of fundamental significance for a variety of advanced chiroptical spectroscopies. The new generation of chiral curved nanographenes offered us the opportunity to study the chiral emission phenomena in the nanometers scale. Herein we reported a distinctive method that combines topological aspects and the density functional theory in order to reach a coherent description of calculated circularly polarized luminescence spectra of negatively curved nanographenes. Our computational plan was defined as a multi-sequence strategy, paying the attention on the relationship between the molecular curvature and the relative spectroscopic properties: 1) the Ball Pivoting Algorithm for the nanographene surface reconstruction; 2) the atom by atom discrete gaussian curvature analysis to establish which DFT functional better approximates the shape of nanographenes backbones; 3) molecular dynamics in the first excited state for accounting the thermal effect; 4) TDDFT benchmark to scrutinize which functional provides the most reliable excitation energies and rotatory strengths for an accurate CPL spectral simulation. The direct merging of the previous steps celebrated the B3LYP (coupled with the 6-311G(d,p) basis set) as the most precise exchange–correlation functional in duplicating exquisitely the CPL profiles of a heterogeneous set of functionalized nanographene.