Lawrence Livermore National Laboratory

First-principles electronic-structure methods[3] require no empirical inputs and compute the total energy and electron density of materials using quantum mechanical techniques. These methods can be used to accurately calculate a wide range of fundamental properties of materials, including the equation of state, elastic moduli, phonon frequencies, and crystallographic phase diagram, among many others. They can also be used to study defect characteristics as well as the electronic and optical properties of materials. Finally, they form the basis of quantum mechanical molecular dynamics simulations. The EOS & Materials Theory Group is pursuing a range of specific research projects that utilize a number of different quantum electronic structure techniques, including the Full-Potential Linear Muffin-Tin Orbital Method (FP-LMTO), the Exact Muffin-Tin Orbital Method (EMTO), the Linearized Augmented Planewave Method (LAPW), the Planewave Pseudopotential Method (PP), and the Finite Element Method (FEM), all of which are based on the local density approximation (LDA) to density functional theory[4], as well as Dynamical Mean-Field Theory (DMFT) and quantum Monte Carlo, which go beyond the LDA in order to more accurately treat the effects of electron correlation. To reach higher temperatures and larger numbers of atoms in QMD simulations, new linearly scaling Spectral Quadrature [1] and quadratically scaling Discontinuous Galerkin [2] electronic structure methods are being developed. State-of-the-art codes have been developed and run on the powerful ASC computers  at LLNL and elsewhere.

Ab initio correlation energies for Ce calculated using Dynamical Mean-Field Theory.

Ab initio correlation energies for Ce calculated
using Dynamical Mean-Field Theory.

Selected Publications

  1. "Spectral Quadrature method for accurate O(N) electronic structure calculations of metals and insulators," P.P. Pratapa, P. Suryanarayana, and J.E. Pask, Comput. Phys. Commun. 200, 96-107 (2016).
  2. "Adaptive local basis set for Kohn-Sham density functional theory in a discontinuous Galerkin framework II: Force, vibration, and molecular dynamics calculations," G. Zhang, L. Lin, W. Hu, C. Yang, and J.E. Pask, submitted, 2015. arXiv: 1510.06489
  3. J. E. Klepeis, Introduction to first-principles electronic structure methods: Application to actinide materials , J. Mater. Res. 21, 2979 (2006).
  4. See, for example, R. O. Jones and O. Gunnarsson, The density functional formalism, its applications and prospects , Rev. Mod. Phys. 61, 689 (1989).

Maintained by   Lorin X. Benedict