Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International



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

Virginia Tech physicists propose path to faster, more flexible robots: Virginia Tech physicists revealed a microscopic phenomenon that could greatly improve the performance of soft devices, such as agile flexible robots or microscopic capsules for drug delivery May 17th, 2024

Gene therapy relieves back pain, repairs damaged disc in mice: Study suggests nanocarriers loaded with DNA could replace opioids May 17th, 2024

Shedding light on perovskite hydrides using a new deposition technique: Researchers develop a methodology to grow single-crystal perovskite hydrides, enabling accurate hydride conductivity measurements May 17th, 2024

Physics

Finding quantum order in chaos May 17th, 2024

International research team uses wavefunction matching to solve quantum many-body problems: New approach makes calculations with realistic interactions possible May 17th, 2024

Chemistry

What heat can tell us about battery chemistry: using the Peltier effect to study lithium-ion cells March 8th, 2024

Two-dimensional bimetallic selenium-containing metal-organic frameworks and their calcinated derivatives as electrocatalysts for overall water splitting March 8th, 2024

Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024

Discovery of new Li ion conductor unlocks new direction for sustainable batteries: University of Liverpool researchers have discovered a new solid material that rapidly conducts lithium ions February 16th, 2024

Quantum Computing

Simulating magnetization in a Heisenberg quantum spin chain April 5th, 2024

Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024

With VECSELs towards the quantum internet Fraunhofer: IAF achieves record output power with VECSEL for quantum frequency converters April 5th, 2024

Chemical reactions can scramble quantum information as well as black holes April 5th, 2024

Discoveries

Virginia Tech physicists propose path to faster, more flexible robots: Virginia Tech physicists revealed a microscopic phenomenon that could greatly improve the performance of soft devices, such as agile flexible robots or microscopic capsules for drug delivery May 17th, 2024

Diamond glitter: A play of colors with artificial DNA crystals May 17th, 2024

Finding quantum order in chaos May 17th, 2024

Advances in priming B cell immunity against HIV pave the way to future HIV vaccines, shows quartet of new studies May 17th, 2024

Announcements

Virginia Tech physicists propose path to faster, more flexible robots: Virginia Tech physicists revealed a microscopic phenomenon that could greatly improve the performance of soft devices, such as agile flexible robots or microscopic capsules for drug delivery May 17th, 2024

Diamond glitter: A play of colors with artificial DNA crystals May 17th, 2024

Finding quantum order in chaos May 17th, 2024

Oscillating paramagnetic Meissner effect and Berezinskii-Kosterlitz-Thouless transition in cuprate superconductor May 17th, 2024

Quantum nanoscience

What is "time" for quantum particles? Publication by TU Darmstadt researchers in renowned journal "Science Advances" May 17th, 2024

Simulating magnetization in a Heisenberg quantum spin chain April 5th, 2024

Optically trapped quantum droplets of light can bind together to form macroscopic complexes March 8th, 2024

Bridging light and electrons January 12th, 2024

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




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project