▎ 摘　　要

The current study has obtained excellent potential nonlinear optical(NLO) materials by combining density functional theory methods with sum-over-states model to predict the second order NLO properties of helical graphene nanoribbons(HGNs) through introducing azulene defects or/and BN units. The introduction of these functional groups deforms the pristine HGN (compression or tension) and enhances obviously the static first hyperpolarizability(