Chinese researchers take the trial and error out materials science

Understanding and tailoring materials’ properties usually requires trial and error, and a bit of luck. But, as a special issue of Computational Materials Science [112, Part B, 405-546, Computational Materials Science in China.] shows, the latest generation of computation techniques and new algorithms can now model novel materials and explore existing ones better than ever before.

China is embracing these new possibilities, making fast progress over the last decade as access to computation resources has become more widespread, according to Xingao Gong of Fudan University. The university is home to a Key Laboratory for Computational Physical Sciences, which has over the last five years successfully used computational tools to clarify long-held misunderstandings about the structure and properties of quaternary semiconductors tagged for future solar cells.

“The profile of computational materials science as a discipline has been rising quickly in China over the last few years,” adds Editor-in-Chief, Professor Susan Sinnott of The Pennsylvania State University. “So this is an ideal time to highlight some of the best work in the field that is being carried out there.”

Exploring the electronic and magnetic properties of materials theoretically begins with a simple model. By considering a few tens or hundreds of atoms at a time, computational methods can calculate properties that are scalable to larger dimensions.

These basic models can be finely tuned to improve accuracy. At the University of Science and Technology of China, for example, Lixin He and colleagues are using atomic orbitals as the basic unit for ab initio electronic structure calculations of silicon, group IV and III-V semiconductors including technologically important GaAs and GaN, as well as alkali and 3d transition metals.

Focusing on orbital physics can be a helpful tactic in unpicking the novel electronic and magnetic behavior of transition metal oxides, which are a platform for many functional devices, according to Hua Wu at Fudan University. The combination of charge, spin, and orbital degrees of freedom in these materials leads to unusual – and useful – effects such as colossal magnetoresistance and multiferroicity.

First principles calculations based on density functional theory (DFT), where quantum mechanical equations determine the density of electrons, are proving effective and versatile in understanding the new generation of planar materials, such as graphene, silicene, and boron nitride. Despite being well known for decades, DFT has been refined in recent years so it can now be used to tailor the physical properties of 2D materials for applications.

DFT can also help unravel the science behind exotic materials like topological insulators, which have an insulating core but surface conducting electrons. Researchers at Beijing Institute of Technology are using this approach to explore such fantastic phenomena as these in solid materials that would be difficult to comprehend by other means.

Likewise, modeling is effective when it comes to identifying and assessing materials for extreme environments. A group at Beihang University is using DFT to identify materials able to withstand the extreme temperatures and irradiation levels inside thermonuclear reactors.

Taking a different approach to models, meanwhile, can yield new insights. A group at Jilin University, for example, has devised a computational method based on a ‘swarm intelligence’ algorithm inspired by natural systems such as ant colonies, bee swarms, and flocks of birds. The self-improving approach works particularly well with atomic and molecular clusters, nanoparticles, and 3D bulk materials.

“I am very excited to see that young scientists in China now have a strong interest in developing new algorithms and first principles approaches based on local atomic orbitals,” says Gong.

The rise of computational methods to understand materials behaviors and properties, and drive new materials’ discovery, has been particularly impressive in China, agrees Baptiste Gault, senior publisher at Elsevier. “It is very timely to provide an overview of the state-of-the-art here and Computational Materials Science is the preeminent forum.” 

This special issue is published in Computational Materials Science- 112, Part B, 405-546
"Computational Materials Science in China".

To find out more about each article included within this special issue, please follow the below links:

CALYPSO structure prediction method and its wide application

The novel electronic and magnetic properties in 5d transition metal oxides system

First-principles investigations on the Berry phase effect in spin–orbit coupling materials

Microscopic mechanism of spin-order induced improper ferroelectric polarization

Orbital physics in transition-metal oxides from first-principles

Theoretical studies of all-electric spintronics utilizing multiferroic and magnetoelectric materials

Recent progresses in real-time local-basis implementation of time dependent density functional theory for electron–nucleus dynamics

Modeling and simulation of helium behavior in tungsten: A first-principles investigation

Recent advances in computational studies of organometallic sheets: Magnetism, adsorption and catalysis

Large-scale ab initio simulations based on systematically improvable atomic basis

First-principles study of two-dimensional van der Waals heterojunctions

Tailoring physical properties of graphene: Effects of hydrogenation, oxidation, and grain boundaries by atomistic simulations