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Surface Passivation for Single-molecule Protein Studies
Published on: April 24, 2014
Surface passivation for tight-binding calculations of covalent solids
1Center for Computational Material Science, Naval Research Laboratory, Washington, DC, USA.
Summary
Explicit hybrid orbital passivation (EHOP) improves cluster simulations for semiconductors. This method offers faster convergence and greater stability for defect calculations compared to other techniques.
Area of Science:
- Computational materials science
- Quantum chemistry
- Solid-state physics
Background:
- Simulating finite portions of larger covalently bonded systems requires surface passivation.
- Existing passivation schemes are primarily studied for wide-gap organic molecules, not narrow-gap semiconductors.
Purpose of the Study:
- To compute the effects of explicit hybrid orbital passivation (EHOP) on atomic structure in a model narrow-gap semiconductor.
- To evaluate EHOP's applicability to minimal atomic orbital basis methods like tight-binding.
Main Methods:
- Developed an explicit hybrid orbital passivation (EHOP) method.
- Applied EHOP to a model bulk, three-dimensional, narrow-gap semiconductor.
- Tested the method by computing forces on atoms near a point defect as a function of cluster geometry.
Main Results:
- EHOP shows faster convergence to the bulk limit for atomic forces compared to pseudo-hydrogen passivation.
- The force on atoms is more stable with respect to cluster center perturbations using EHOP.
- EHOP eliminates the need for parameterizing interactions between system and passivating atoms.
Conclusions:
- EHOP is a robust and efficient passivation technique for cluster calculations of non-periodic defects in semiconductors.
- The method is suitable for hybrid quantum-mechanical/interatomic potential simulations of large systems.
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