ICME GRP2 HW1
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Abstract
Bulk modulus, energy cutoff, lattice constant, energy/atom, elastic constants, and formation energies were determined for the FCC, BCC, and HCP aluminum structures using the Density Functional Theory package VASP. These were used to bridge to the nanoscale where LAMMPS was used to attempt to determine the constants required for the MEAM potential.
Introduction
Density Function Theory (DFT) is a method used to investigate material properties at the electronic scale. These material properties may then be passed up through upscaling to the nanoscale by incorporating them into a molecular dynamics potential such as the Modified Embedded Atom Method (MEAM). These potentials describe how the atoms should interact with one another.
Discussion
Upscaling to the atomistic scale requires several material properties that must be obtained to create an atomic potential such as MEAM. If these values are not available experimentally, DFT values can be used to approximate the values to create the potential. There are many material properties that are required when trying to create an atomistic potential including the lattice parameter, cohesive energy, bulk modulus, energy difference from other phases, elastic moduli, vacancy formation energy, interstitial formation energy, stacking fault energies, surface formation energy, surface adsorption energy, and the generalized stacking fault energy curve[1]. These material properties will allow for the fitting of a potential using LAMMPS so that more accurate material structure and energies can be found when atomistic simulations are run.
References
- ↑ M.F. Horstemeyer. Integrated Computational Materials Engineering (ICME) for Metals: Using Multiscale Modeling to Invigorate Engineering Design with Science. Wiley, 2012.
