News

CEST researchers pave the way for calculating circular dichroism (CD) spectra more efficiently

Researchers led by Xi Chen have published a new study to calculate CD spectra of metal nanoclusters in an improved manner
A graphic showing CD spectra of a metal nanocluster
Graphic taken from Makkonen et al. J. Chem. Phys. 154, 114102 (2021)
A photo showing researcher Esko Makkonen
First author Esko Makkonen

Members of the CEST group published a recent paper introducing a novel method to calculate CD spectra in the open source GPAW code. The publication shows that the implemented approach is more efficient than the commonly used linear-response method and can easily calculate CD spectra of nanoscale systems, such as hybrid silver clusters composed of over 1000 atoms.

Recording CD spectra is a very powerful method to study the chiral optical properties and detect small structure changes in chiral molecules, DNA, proteins and nanoclusters, to name a few. However, the computational cost of commonly used linear-response time-dependent density functional theory (TDDFT) methodology increases drastically with the system size under observation, and can typically only be applied to small systems. To overcome this challenge, researchers Esko MakkonenTuomas RossiPatrick Rinke and Xi Chen worked with collaborators from Jyväskylä, Spain and Colombia to implement a more efficient approach based on real-time TDDFT to calculate CD spectra. The published code offers both linear combination of atomic orbitals (LCAO) and grid modes. The LCAO mode is beneficial for large systems, while the grid mode is suitable for small molecules and benchmark purposes, thus making this new method extremely versatile.

The authors tested this new implementation on various systems. In all test cases, the calculations show high efficiency and agree well with experimental results and reference computations. Driven by this initial success, the group is now ready to study many more chiral nanoclusters. The aim of this work is to discover the origin of chiral optical properties in nanoclusters, and design metal clusters which are useful as chiral sensors.

This paper is published in The Journal of Chemical Physics. https://doi.org/10.1063/5.0038904

  • Published:
  • Updated:
Share
URL copied!

Read more news

Icepeak_Tokyo_olympic outfit
Research & Art Published:

Aalto student idea developed into the The Finnish Olympic team’s apparel to be worn in the Tokyo games

Luhta Sportswear Company and Aalto university collaboration resulted in Olympic games apparel.
ENRIO 2021 congress logo banner
Research & Art Published:

ENRIO 2021 congress takes place online on 27-29 September

The main themes of the congress are research integrity in open science and EU data protection laws. Registration opens on 3 May.
Professori Joni Pajarinen. Kuva: Aalto-yliopisto/ Kukka Maria Rosenlund
Research & Art Published:

Professor Joni Pajarinen believes in the future potential of robots 

In the future robots will work and learn independently, also with humans, and will no longer merely carry out programmed instructions. 
Pauliina Pasasen väitös käsitteli valokuvaajaksi oppimista.
Research & Art Published:

‘A photographer is born together with the camera, through many different encounters’

In her doctoral thesis, Pauliina Pasanen examined learning to be a photographer.