Plasmon Dynamics in Nanoclusters: Dephasing Revealed by Excited States Evaluation.

The photocatalytic efficiency of materials such as graphene and noble metal nanoclusters depends on their plasmon lifetimes. Plasmon dephasing and decay in these materials is thought to occur on ultrafast time scales, ranging from a few femtoseconds to hundreds of femtoseconds and longer. Here we focus on understanding the dephasing and decay pathways of excited states in small lithium and silver clusters and in plasmonic states of the π-conjugated molecule anthracene, providing insights that are crucial for interpreting optical properties and photophysics.

Convergence of Time-Derivative Nonadiabatic Couplings in Plane-Wave DFT Calculations.

Accurate prediction of charge carrier relaxation rates is essential to design molecules and materials with the desired photochemical properties for applications like photocatalysis and solar energy conversion. Nonadiabatic molecular dynamics allows one to simulate the relaxation process of excited charge carriers. Plane-wave density functional theory (DFT) calculations make the time-derivative nonadiabatic couplings (TNACs) simple to compute because the basis is independent of the atomic positions.

Evolution of plasmon-like excited states in silver nanowires and nanorods.

Silver nanowires and nanorods are useful prototypical systems to study the emergence of plasmons within a quantum mechanical context because their high aspect ratios enable plasmons to emerge in smaller systems than for roughly spherical nanoclusters. Here, we quantify the plasmon-like character of the excited states of silver nanorods and nanowires based on three nearly orthogonal criteria: (1) collectivity, (2) dipole additivity, and (3) superatomic character. Based on these three criteria, we classify the excited states as plasmon-like, collective, single-particle, interband, or as intermediate between these categories.