Ben Haley

Objective:

• Implement atomistic strain calculation for nanowires and quantum dots in OMEN
• Increase speed of matrix construction for recomputed Hamiltonian in NEMO 3D
• Track memory usage in OMEN
• Develop scripting interfaces for OMEN

Approach:

• Serial (1D decomposition) and parallel (3D decomposition) Valence Force Field calculation using C++ in OMEN
• Explicitly unroll loops over orbitals in NEMO 3D matrix element calculation
• Implement memory allocation in OMEN using the NEMO Math Library
• Develop a new language, OWL, for OMEN scripting, as well as Python, Tcl, and Ruby bindings for OMEN

Impacts and Results:

• Correctly handling atomic displacements allows for truly realistic simulations of both nanowires and quantum dots
• Explicit Hamiltonian construction increased the speed of NEMO 3D recompute calculations by a factor of five
• Identifying memory usage bottlenecks in OMEN leads to streamlined and optimized performance
• Top level scripts in OWL, Python, Ruby, and Tcl allow specific modules of OMEN to run and interact with other programs
• The changes to the OMEN code base for the scripting interfaces allow for the development of a material database, which can be called from OMEN or any other code which needs material properties.