Nanotechnology Now





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > CFN – Theoretical Chemistry: Pathbreaking Review Paper - Density Functional Theory (DFT) for Open-shell Molecules: Spin Calculations

1) An experimental structure of a transition metal cluster based on the elements of chromium (Cr) and dysprosium (Dy). Its unpaired electrons lead to special magnetic properties (yellow arrows) that allow for its use as single molecule magnet.
Source: CFN, Professor Annie Powell, research project C 1.2 “Synthesis and Characterization of New Nano-Scale Aggregates Displaying Cooperative Magnetic Coupling*
1) An experimental structure of a transition metal cluster based on the elements of chromium (Cr) and dysprosium (Dy). Its unpaired electrons lead to special magnetic properties (yellow arrows) that allow for its use as single molecule magnet.

Source: CFN, Professor Annie Powell, research project C 1.2 “Synthesis and Characterization of New Nano-Scale Aggregates Displaying Cooperative Magnetic Coupling*

Abstract:
The review paper on the consideration of spin in density functional theory (DFT), published by the scientists Dr. Christoph Jacob from the Center for Functional Nanostructures (CFN) of Karlsruhe Institute of Technology and Professor Markus Reiher from ETH Zurich, functions to close a major knowledge gap in theoretical chemistry.

CFN – Theoretical Chemistry: Pathbreaking Review Paper - Density Functional Theory (DFT) for Open-shell Molecules: Spin Calculations

Karlsruhe, Germany | Posted on November 30th, 2012

DFT is an important tool within the field of theoretical chemistry. It is used to calculate the properties of molecules and solids, such as binding lengths and energies.

For the time being, molecules with paired electrons only can be calculated using DFT. For molecules with unpaired electrons, also called open-shell systems, DFT cannot yet be applied in a satisfactory manner. Unpaired electrons lead to a magnetic moment, the spin, and its consideration by DFT remains quite challenging.

In transition metals and their compounds, these unpaired electrons offer a rich and complex chemistry, making them interesting for a number of applications. Change of spin in bio-inorganic reactions, for instance, may be responsible for a transition metal complex acting as a catalyst. Transition metal clusters in single molecule magnets are integral as connections of storage elements in (quantum) information processing.

The large scope of applications explains the high scientific interest in calculating the behavior of open-shell systems using theoretical methods. In past years, scientists Jacob and Reiher began systematic studies in this field and developed solution approaches. Currently, they have published their detailed results in the International Journal of Quantum Chemistry in the form of a tutorial that is highly useful for both beginners and advanced practitioners.

"Understanding of the underlying exact theory is a prerequisite for the development of a reliable approximation method. That is why we first sum up these fundamentals," Jacob says. The authors explain the non-relativistic treatment of spin for a single electron - the subject of many basic studies in quantum mechanics. They then analyze the treatment of spin using the Hohenberg-Kohn and Kohn-Sham DFT. Various methods of considering spin in DFT are described and analyzed. Jacob and Reiher also study the relativistic DFT. Finally, proposals are made as to how spin approximation can be improved within the DFT.

Density Functional Theory (DFT)

In the 1960s, fostered by the newly emerging computer generation, quantum chemistry developed into its own field of theoretical chemistry. Until then, it had been scarcely possible to describe complex structures, such as molecules, using mathematical equations to calculate their behavior. Although the underlying laws were well known, they were too complex to be managed using calculations alone. The calculation of chemical bonds between the atoms of a molecule became possible only after the development of approximation methods and the more ubiquitous use of computers in the 1960s. In chemistry, this development marked the transition from an experimental to a computable science. Two leading fundamental scientists of that time were Walter Kohn and John A. Pople. In 1998, they were awarded the Noble Prize for Chemistry, Kohn for the development of the DFT and Pople for the development of computation methods in quantum chemistry. Since then, computing capacity has multiplied exponentially and DFT has developed further, such that it can now be used for larger and more specific structures.

The Authors:

Christoph R. Jacob has been heading the Junior Research Group for Theoretical Chemistry at the Center for Functional Nanostructures (CFN) of the Karlsruhe Institute of Technology (KIT) since 2010. He studied chemistry and mathematics at the University of Marburg and the University of Karlsruhe (today's KIT). In 2007, he was conferred his doctorate by the VU University of Amsterdam (The Netherlands). He worked at Auckland University (New Zealand) and ETH Zurich (Switzerland).

Markus Reiher has been a professor of theoretical chemistry at ETH Zurich (Switzerland) since 2006. He studied chemistry, was conferred his doctorate in theoretical chemistry by the University of Bielefeld, and earned his post-doctoral lecture qualification at the University of Erlangen in 2002. He then worked as a private lecturer at the University of Erlangen and the University of Bonn. In 2005, he accepted a professorship for physical chemistry at the University of Jena. A year later, he accepted a call by ETH Zurich.

####

About DFG Center for Functional Nanostructures (CFN)
The DFG Center for Functional Nanostructures (CFN) focuses on an important area of nanotechnology, functional nanostructures. Its excellent interdisciplinary and international research is aimed at representing nanostructures with new technical functions and at making the first step from fundamental research to application. Presently, more than 250 scientists and engineers are cooperating in more than 80 partial projects at the CFN in Karlsruhe. The focus is placed on the areas of nanophotonics, nanoelectronics, molecular nanostructures, nanobiology, and nanoenergy. The building of the CFN is located on the Campus South of the Karlsruhe Institute of Technology.

www.cfn.kit.edu



* First Publication of image 1: Julia Rinck, Ghenadie Novitchi, Willem Van den Heuvel, Liviu Ungur, Yanhua Lan, Wolfgang Wernsdorfer, Christopher E. Anson, Liviu F. Chibotaru, and Annie K. Powell, Angew. Chem. Int. Ed. 2010, 49, Single-Molecule Magnets, p. 7585

For more information, please click here

Contacts:
Tatjana Erkert
KIT / CFN, Wolfgang-Gaede-Str. 1a
Karlsruhe, BW, 76139 Germany
Phone: ++49 721 608 43409

Copyright © DFG Center for Functional Nanostructures (CFN)

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

SouthWest NanoTechnologies Introduces AgeNT™ Transparent Conductor System at SID Display Week, Booth #543 May 28th, 2015

New technique speeds nanoMRI imaging: Multiplexing technique for nanoscale magnetic resonance imaging developed by researchers in Switzerland cuts normal scan time from two weeks to two days May 28th, 2015

Squeezed quantum cats May 28th, 2015

Physics

Linking superconductivity and structure May 28th, 2015

How spacetime is built by quantum entanglement: New insight into unification of general relativity and quantum mechanics May 28th, 2015

Squeezed quantum cats May 28th, 2015

Chemistry

Chemists discover key reaction mechanism behind the highly touted sodium-oxygen battery May 28th, 2015

Quantum Computing

Squeezed quantum cats May 28th, 2015

Advance in quantum error correction: Protocol corrects virtually all errors in quantum memory, but requires little measure of quantum states May 27th, 2015

Researchers discover 'swing-dancing' pairs of electrons: Findings set the stage for room-temperature superconductivity and the transformation of high-speed rail, quantum computers May 14th, 2015

Researchers build new fermion microscope: Instrument freezes and images 1,000 individual fermionic atoms at once May 13th, 2015

Discoveries

Chemists discover key reaction mechanism behind the highly touted sodium-oxygen battery May 28th, 2015

New technique speeds nanoMRI imaging: Multiplexing technique for nanoscale magnetic resonance imaging developed by researchers in Switzerland cuts normal scan time from two weeks to two days May 28th, 2015

Squeezed quantum cats May 28th, 2015

New chip makes testing for antibiotic-resistant bacteria faster, easier: Researchers at the University of Toronto design diagnostic chip to reduce testing time from days to one hour, allowing doctors to pick the right antibiotic the first time May 28th, 2015

Announcements

Chemists discover key reaction mechanism behind the highly touted sodium-oxygen battery May 28th, 2015

New technique speeds nanoMRI imaging: Multiplexing technique for nanoscale magnetic resonance imaging developed by researchers in Switzerland cuts normal scan time from two weeks to two days May 28th, 2015

Squeezed quantum cats May 28th, 2015

New chip makes testing for antibiotic-resistant bacteria faster, easier: Researchers at the University of Toronto design diagnostic chip to reduce testing time from days to one hour, allowing doctors to pick the right antibiotic the first time May 28th, 2015

Quantum nanoscience

Physicists solve quantum tunneling mystery: ANU media release: An international team of scientists studying ultrafast physics have solved a mystery of quantum mechanics, and found that quantum tunneling is an instantaneous process May 27th, 2015

Quantum physics on tap - Nano-sized faucet offers experimental support for longstanding quantum theory May 16th, 2015

Researchers discover 'swing-dancing' pairs of electrons: Findings set the stage for room-temperature superconductivity and the transformation of high-speed rail, quantum computers May 14th, 2015

Researchers build new fermion microscope: Instrument freezes and images 1,000 individual fermionic atoms at once May 13th, 2015

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project