T-12 contributes to Los Alamos efforts in the development and application of Monte Carlo techniques through the LDRD project "Monte Carlo for the 21st Century," aka Monte Carlo 21.

Under this program T-12 staff member Lawrence Pratt works on:

• specialized Monte Carlo methods for simulation of models of complex solutions of water-oil-surfactant, polymer, and liquid crystal systems.
• advanced statistical analysis of Monte Carlo simulation data.
• adapting advanced Monte Carlo methods for transport problems to quantum Monte Carlo applications.

The viewgraphs (as pdf files) for some recent presentations follow. This permits the audience access to the slides before the talk and probably not all the slides would be shown.

• `` Construction of Simulation Wavefunctions for Aqueous Species: D₃O⁺.'' [Telluride Workshop on Condensed Phase Dynamics]

Some Research Papers:

• G. G. Hoffman, L. R. Pratt, and R. A. Harris, Chem. Phys. Letts. 148, 313 (1988): ``Monte Carlo integration of density functional theory: Fermions in a harmonic well.''
• L. R. Pratt, Phys. Rev. A 40, 6077 (1989): ``Lower bound on the ground state energies of atoms and molecules by variational quantum Monte Carlo.''
• L. R. Pratt and R. A. Keller, J. Phys. Chem. 97, 10254 (1993): ``Estimate of the probability of diffusional misordering in high-speed DNA sequencing.''
• M. A. Gomez and L. R. Pratt, J. Chem. Phys. 109, 8783(1998): `` Construction of Simulation Wavefunctions for Aqueous Species: D₃O⁺.''

Sampled configuration of water (background), oil (red), H₄T₄ surfactant (blue) for 2d Ising model on 128x128 square lattice at T = 0.84 T_c on the water-oil coexistence curve.  

An illustration how the IRS algorithm works for such cases: H₄T₄ surfactant for 2d Ising model on 32x32 square lattice at T = 0.88 T_c on the water-oil coexistence curve.