Supercell issues in density functional calculations.

Conference · 01 April 2005

OSTI ID:969545

Schultz, Peter Andrew

Simulations within density functional theory (DFT) are a common component of research into the physics of materials. With the broad success of DFT, it is easily forgotten that computational DFT methods invariably do not directly represent simulated properties, but require careful construction of models that are computable approximations to a physical property. Perhaps foremost among these computational considerations is the routine use of the supercell approximation to construct finite models to represent infinite systems. Pitfalls in using supercells (k-space sampling, boundary conditions, cell sizes) are often underappreciated. We present examples (e.g. vacancy defects) that exhibit a surprising or significant dependence on supercells, and describe workable solutions. We describe procedures needed to construct meaningful models for simulations of real material systems, focusing on k-space and cell size issues.

• Research Organization: Sandia National Laboratories
• Sponsoring Organization: USDOE
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 969545
• Report Number(s): SAND2005-2541C
• Conference Information: Proposed for presentation at the American Physical Society 2005 March Meeting held March 21-25, 2005 in Los Angeles, CA.
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
97 MATHEMATICS AND COMPUTING
APPROXIMATIONS
BOUNDARY CONDITIONS
DENSITY FUNCTIONAL METHOD
MATERIALS
PHYSICAL PROPERTIES
SAMPLING
VACANCIES