The potential, limitations, and challenges of divide and conquer quantum electronic structure calculations on energetic materials

Technical Report · Wed Feb 01 00:00:00 EST 2012

DOI:https://doi.org/10.2172/1038199· OSTI ID:1038199

Magyar, Rudolph J. ^[1]; Tucker, Jon R. ^[1]

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1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

High explosives are an important class of energetic materials used in many weapons applications. Even with modern computers, the simulation of the dynamic chemical reactions and energy release is exceedingly challenging. While the scale of the detonation process may be macroscopic, the dynamic bond breaking responsible for the explosive release of energy is fundamentally quantum mechanical. Thus, any method that does not adequately describe bonding is destined to lack predictive capability on some level. Performing quantum mechanics calculations on systems with more than dozens of atoms is a gargantuan task, and severe approximation schemes must be employed in practical calculations. We have developed and tested a divide and conquer (DnC) scheme to obtain total energies, forces, and harmonic frequencies within semi-empirical quantum mechanics. The method is intended as an approximate but faster solution to the full problem and is possible due to the sparsity of the density matrix in many applications. The resulting total energy calculation scales linearly as the number of subsystems, and the method provides a path-forward to quantum mechanical simulations of millions of atoms.

• Research Organization: Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 1038199
• Report Number(s): SAND--2012-1298
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
99 GENERAL AND MISCELLANEOUS
APPROXIMATIONS
ATOMS
BONDING
CALCULATION METHODS
CHEMICAL EXPLOSIVES
CHEMICAL REACTIONS
COMPUTERIZED SIMULATION
DENSITY MATRIX
ELECTRONIC STRUCTURE
EXPLOSIONS
EXPLOSIVES
HARMONICS
QUANTUM ELECTRONICS
QUANTUM MECHANICS
WEAPONS