Journal of Materials Research

Outstanding Meeting Papers

Robust quantum-based interatomic potentials for multiscale modeling in transition metals

John A. Moriartya1 c1, Lorin X. Benedicta1, James N. Gloslia1, Randolph Q. Hooda1, Daniel A. Orlikowskia1, Mehul V. Patela1, Per Söderlinda1, Frederick H. Streitza1, Meijie Tanga1 and Lin H. Yanga1

a1 Lawrence Livermore National Laboratory, University of California, Livermore, California 94551-0808

Abstract

First-principles generalized pseudopotential theory (GPT) provides a fundamental basis for transferable multi-ion interatomic potentials in transition metals and alloys within density-functional quantum mechanics. In the central body-centered cubic (bcc) metals, where multi-ion angular forces are important to materials properties, simplified model GPT (MGPT) potentials have been developed based on canonical d bands to allow analytic forms and large-scale atomistic simulations. Robust, advanced-generation MGPT potentials have now been obtained for Ta and Mo and successfully applied to a wide range of structural, thermodynamic, defect, and mechanical properties at both ambient and extreme conditions. Selected applications to multiscale modeling discussed here include dislocation core structure and mobility, atomistically informed dislocation dynamics simulations of plasticity, and thermoelasticity and high-pressure strength modeling. Recent algorithm improvements have provided a more general matrix representation of MGPT beyond canonical bands, allowing improved accuracy and extension to f-electron actinide metals, an order of magnitude increase in computational speed for dynamic simulations, and the development of temperature-dependent potentials.

(Received September 27 2005)

(Accepted November 30 2005)

(Online publication March 2006)

Key Words:

  • Dislocations;
  • Rapid solidification;
  • Simulation

Correspondence:

c1 Address all correspondence to this author. e-mail: moriarty2@llnl.gov This paper was selected as the Outstanding Meeting Paper for the 2005 MRS Spring Meeting Symposium EE Proceedings, Vol. 882E.

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