Publications

Tranchida, Julien G.; Wood, Mitchell A.; Moore, Stan G.; Plimpton, Steven J.; Thompson, Aidan P.; Thibaudeau, Pascal T.

Abstract not provided.

Yarrington, Cole Y.; Kittell, David E.; Bolintineanu, Dan S.; Lechman, Jeremy B.; Wood, Mitchell A.; Knepper, Robert; Olles, Joseph D.; Thompson, Aidan P.; Wixom, Ryan R.

Abstract not provided.

Yarrington, Cole Y.; Kittell, David E.; Bolintineanu, Dan S.; Lechman, Jeremy B.; Wood, Mitchell A.; Knepper, Robert; Olles, Joseph D.; Thompson, Aidan P.; Wixom, Ryan R.

Abstract not provided.

Journal of Chemical Physics

Wood, Mitchell A.; Thompson, Aidan P.

The Spectral Neighbor Analysis Potential (SNAP) is a classical interatomic potential that expresses the energy of each atom as a linear function of selected bispectrum components of the neighbor atoms. An extension of the SNAP form is proposed that includes quadratic terms in the bispectrum components. The extension is shown to provide a large increase in accuracy relative to the linear form, while incurring only a modest increase in computational cost. The mathematical structure of the quadratic SNAP form is similar to the embedded atom method (EAM), with the SNAP bispectrum components serving as counterparts to the two-body density functions in EAM. The effectiveness of the new form is demonstrated using an extensive set of training data for tantalum structures. Similar to artificial neural network potentials, the quadratic SNAP form requires substantially more training data in order to prevent overfitting. The quality of this new potential form is measured through a robust cross-validation analysis.

Wood, Mitchell A.; Kittell, David E.; Yarrington, Cole Y.; Thompson, Aidan P.

Abstract not provided.

Wood, Mitchell A.; Thompson, Aidan P.

Abstract not provided.

Wood, Mitchell A.; Kittell, David E.; Yarrington, Cole Y.; Thompson, Aidan P.

Abstract not provided.

Wood, Mitchell A.; Kittell, David E.; Yarrington, Cole Y.; Thompson, Aidan P.

Abstract not provided.

Kittell, David E.; Yarrington, Cole Y.; Wood, Mitchell A.; Thompson, Aidan P.

Abstract not provided.

Wood, Mitchell A.; Thompson, Aidan P.

The purpose of this short contribution is to report on the development of a Spectral Neighbor Analysis Potential (SNAP) for tungsten. We have focused on the characterization of elastic and defect properties of the pure material in order to support molecular dynamics simulations of plasma-facing materials in fusion reactors. A parallel genetic algorithm approach was used to efficiently search for fitting parameters optimized against a large number of objective functions. In addition, we have shown that this many-body tungsten potential can be used in conjunction with a simple helium pair potential1 to produce accurate defect formation energies for the W-He binary system.

Wood, Mitchell A.; Kittell, David E.; Yarrington, Cole Y.; Thompson, Aidan P.

Abstract not provided.

Thompson, Aidan P.; Wood, Mitchell A.

Abstract not provided.

Yarrington, Cole Y.; Thompson, Aidan P.; Kittell, David E.; Wood, Mitchell A.

Abstract not provided.