Quantum leap: computational approach launches new paradigm in electronic structure theory

A group of Michigan State University researchers specializing in quantum calculations has proposed a radically new computational approach to solving the complex many-particle Schrodinger equation, which holds the key to explaining the motion of electrons in atoms and molecules.

By understanding the details of this motion, one can determine the amount of energy needed to transform reactants into products in a chemical reaction, or the color of light absorbed by a molecule, and ultimately accelerate the design of new drugs and materials, better catalysts and more efficient energy sources.

The work, led by Piotr Piecuch, university distinguished professor in the Department of Chemistry and adjunct professor in the Department of Physics and Astronomy in the College of Natural Science, was published recently in Physical Review Letters. Also involved in the work are fourth-year graduate student J. Emiliano Deustua and senior postdoctoral associate Jun Shen. The group provides details for a new way of obtaining highly accurate electronic energies by merging the deterministic coupled-cluster and stochastic (randomly determined) Quantum Monte Carlo approaches.

"Instead of insisting on a single philosophy when solving the electronic Schrodinger equation, which has historically been either deterministic or stochastic, we have chosen a third way," Piecuch said.

"As one of the reviewers noted, the essence of it is remarkably simple: use the stochastic approach to determine what is important and the deterministic approach to determine the important, while correcting for the information missed by stochastic sampling."

Solving the Schrodinger equation for the many-electron wave function has been a key challenge in quantum chemistry for decades. Anything other than a one-electron problem, such as a hydrogen atom, requires resorting to numerical methods, converted into sophisticated computer programs, such as those developed by Piecuch and his group. The main difficulty has been the intrinsic complexity of the electronic motion, which quantum chemists and physicists call "electron correlation."

The new idea is to use the stochastic methods to identify the leading wave function components and the deterministic coupled-cluster computations, combined with suitable energy corrections, to provide the missing information. The merging of deterministic and stochastic approaches as a general method of solving the many-particle Schrodinger equation may also impact other areas, such as nuclear physics.

"In the case of nuclei, instead of being concerned with electrons, one would use our new approach to solve the Schrodinger equation for protons and neutrons," Piecuch said.

"The mathematical and computational issues are similar. Just like chemists want to understand the electronic structure of a molecule, nuclear physicists want to unravel the structure of the atomic nucleus. Once again, solving the many-particle Schrodinger equation holds the key."

Intel chief says chip flaw damage contained by industry
Las Vegas (AFP) Jan 9, 2018
Intel chief Brian Krzanich said Monday the impact of a recently discovered vulnerability in computer chips has been limited due to "remarkable" collaboration by the tech industry. Krzanich took the unusual step of addressing the security issue as he delivered a keynote ahead of the opening of the huge Consumer Electronics Show in Las Vegas, an industry event expected to draw some 180,000 peo ... read more

Related Links
Michigan State University
Computer Chip Architecture, Technology and Manufacture
Nano Technology News From SpaceMart.com

Thanks for being there;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Monthly Supporter
$5+ Billed Monthly

SpaceDaily Contributor
$5 Billed Once

credit card or paypal