Nanotechnology Now

Our NanoNews Digest Sponsors

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

Graphene is strong, but is it tough? Berkeley Lab scientists find that polycrystalline graphene is not very resistant to fracture February 7th, 2016

Lithium battery catalyst found to harm key soil microorganism February 7th, 2016

Scientists take key step toward custom-made nanoscale chemical factories: Berkeley Lab researchers part of team that creates new function in tiny protein shell structures February 6th, 2016

Discovery of the specific properties of graphite-based carbon materials February 6th, 2016

Chemistry

Scientists take key step toward custom-made nanoscale chemical factories: Berkeley Lab researchers part of team that creates new function in tiny protein shell structures February 6th, 2016

Discovery of the specific properties of graphite-based carbon materials February 6th, 2016

Nature Materials: Smallest lattice structure worldwide: 3-D lattice with glassy carbon struts and braces of less than 200 nm in diameter has higher specific strength than most solids February 3rd, 2016

Physics

Polar vortices observed in ferroelectric: New state of matter holds promise for ultracompact data storage and processing February 4th, 2016

The quantum fridge: It all comes down to quantum physics: scientists at TU Wien have analyzed why some gases can be cooled down to extremely low temperatures February 2nd, 2016

Unconventional superconductivity near absolute zero temperature: Quantum critical point could be the reason for high temperature superconductivity February 2nd, 2016

Quantum Computing

New invention revolutionizes heat transport February 1st, 2016

A new quantum approach to big data January 25th, 2016

Bismuth-based nanoribbons show 'topological' transport, potential for new technologies January 22nd, 2016

Mechanical quanta see the light January 20th, 2016

Discoveries

Graphene is strong, but is it tough? Berkeley Lab scientists find that polycrystalline graphene is not very resistant to fracture February 7th, 2016

Lithium battery catalyst found to harm key soil microorganism February 7th, 2016

Scientists take key step toward custom-made nanoscale chemical factories: Berkeley Lab researchers part of team that creates new function in tiny protein shell structures February 6th, 2016

Discovery of the specific properties of graphite-based carbon materials February 6th, 2016

Announcements

Graphene is strong, but is it tough? Berkeley Lab scientists find that polycrystalline graphene is not very resistant to fracture February 7th, 2016

Lithium battery catalyst found to harm key soil microorganism February 7th, 2016

Scientists take key step toward custom-made nanoscale chemical factories: Berkeley Lab researchers part of team that creates new function in tiny protein shell structures February 6th, 2016

Discovery of the specific properties of graphite-based carbon materials February 6th, 2016

Quantum nanoscience

Spin dynamics in an atomically thin semi-conductor February 1st, 2016

New record in nanoelectronics at ultralow temperatures January 28th, 2016

Leti to Host Workshop on New Photonics Applications During SPIE Photonics West: Researchers also Will Present Four Invited Papers At Feb. 13-18 Conference, 14 Papers, Overall January 25th, 2016

Mechanical quanta see the light January 20th, 2016

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







Car Brands
Buy website traffic