Real-time time-dependent density functional theory implementation of electronic circular dichroism applied to nanoscale metal-organic clusters.

Esko Makkonen,Mikael Kuisma,Tuomas P Rossi,Ask Hjorth Larsen,Xi Chen,Patrick Rinke,Olga Lopez-Acevedo

doi:10.1063/5.0038904

Abstract

Electronic circular dichroism (ECD) is a powerful spectroscopy method for investigating chiral properties at the molecular level. ECD calculations with the commonly used linear-response time-dependent density functional theory (LR-TDDFT) framework can be prohibitively costly for large systems. To alleviate this problem, we present here an ECD implementation within the projector augmented-wave method in a real-time-propagation TDDFT framework in the open-source GPAW code. Our implementation supports both local atomic basis sets and real-space finite-difference representations of wave functions. We benchmark our implementation against an existing LR-TDDFT implementation in GPAW for small chiral molecules. We then demonstrate the efficiency of our local atomic basis set implementation for a large hybrid nanocluster and discuss the chiroptical properties of the cluster.

Highlights

Chirality is an essential property in several branches of science and technology
We use a benchmark molecule (R)-methyloxirane to validate that our RT-Time-dependent density-functional theory (TDDFT) implementation can produce the same Electronic circular dichroism (ECD) spectra as the LR-TDDFT implementation in both LCAO and the real-space grid mode
We presented a RT-TDDFT implementation for calculating ECD in the GPAW package, which supports both the LCAO mode and grid mode

Summary

Introduction

Chirality is an essential property in several branches of science and technology. Chiral molecules play a fundamental role in biological activities; for example, DNA double-helices are righthanded and amino acids are left-handed. R-enantiomer thalidomide is effective against morning sickness for pregnant women, but the S-species produce fetal deformations.. Chiral molecules and chiral nanomaterials have many potential applications in catalysis, sensors, spintronics, optoelectronics, and nanoelectronics.. The determination of the handedness of chiral systems is of paramount importance R-enantiomer thalidomide is effective against morning sickness for pregnant women, but the S-species produce fetal deformations. In addition, chiral molecules and chiral nanomaterials have many potential applications in catalysis, sensors, spintronics, optoelectronics, and nanoelectronics.

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