Researchers around the world are finding great value in ReaxFF’s reactive force field

UNIVERSITY PARK, PA. – More than 1,600 researchers on six of the world’s seven continents have pParameters for a ReaxFF reaction force field developed by a Penn State researcher and used as a valuable research tool in fields as diverse as biomaterials, polymers, batteries, and 3D printing.

While many in science fiction may think of a force field as an invisible barrier of energy, in this case a Force field is a set of parameters and equations used to calculate forces between atoms and molecules. ReaxFF is a force field method based on bond orders and a powerful computing tool that enables reactive simulations on complex materials such as B. allows an atom thick 2D materials.

The ReaxFF method was invented by Adri van Duin, Penn State Distinguished Professor of MechanicsHe worked at the University of Newcastle upon Tyne (UK) and in Bill Goddard’s group at the California Institute of Technology.

“They are used for so-called molecular dynamics simulations, which essentially means that we can follow the movement of atoms” as a function of time, ”said van Duin. “But one unique thing is that you can make and break chemical bonds during these simulations.”

By ReaxFF, researchers can gain extensive knowledge down to the nano range of the material they are investigating in order to optimize these materials and develop new material concepts. It’s cheaper and more efficient than quantum mechanics, which is more accurate and transferrable but much more computationally intensive.

“We have a very good set of parameters for many types of water-based chemistry and that is clearly something that is repeated in many different applications, ”said van Duin.

“One interesting aspect is how we can combine ReaxFF with other simulation methods, ”said van Duin. “For example, recently I worked with Yuan Xuan, an associate professor of mechanical engineering who does numerical flow simulations. By using ReaxFF, he can give his group real-time reaction dynamics information that they can feed into his research tools. and then he really can simulate a entire reactor. W.He can give him the conditions he needs to actually simulate the actual conditions of the fuel reactor. ”

The parameters can even be used in biological applications such as B. Biopolymer Materials, natural polymers produced by living cells, such as cellulose, starch, and proteins.

“The The ReaxFF method is particularly well suited for people who want to simulate how biopolymers interact with inorganic surfaces, ”said van Duin. “You can work very comfortably with it because you handle this interface very well.”

As more people, nationally and internationallyHaving used parameters, the researchers adjust the ReaxFF parameters for their own use.

“I have heard from groups around the world who actually independently developed force field parameters and established their own application domains, ”said van Duin. “Right now there are often five to ten publications on these particular methods in a given week. Although I try to stay up to date on this literature, I find it difficult to keep track of what everyone is doing with ReaxFF these days. ”

TThose interested in hoses can request the parameters for the ReaxFF by email from the van Duin group.

“Usually it can be a bit of an email exchange where we discuss, okay, what exactly are we trying to simulate?” Van Duin said: “And I tell you These parameters can be useful, or maybe even something that is exactly what they need, or something that comes close to what they need. In the latter case, we tell them to try the simulations, not do anything big yet, just test it and see if you see the right things. If it looks promising, you can enlarge it. ”

Sometimes van Duin receive a request for a reactive force field that they cannot offer. If the scope of the request is scalable, van Duin sees this as an opportunity.

“These can be an opportunity that has led to projects in my group, maybe the PhD students in my group can work with them to put together a force field, ”said van Duin.

While the more than 1,600 inquiries for the The parameters of ReaxFF are certainly impressive, van Duin is looking for ways to expand access for even more inquiries. As a faculty researcher in the Materials Research Institute‘s Two-Dimensional Crystal Consortium (2DCC), he’s exploring ways to integrate 2DCC resources to meet requests.

“We want to see if we can improve the user experience by connecting it to the 2DCC extension program, especially for 2D material requirement, ”said van Duin. “We can make this whole concept more user-friendly and also have an automatic way that when people say ‘the set of parameters I need doesn’t exist’ and somehow that can be automatically converted into an external user request.” And then it will an active project of my group. ”