First Year Report
Mon May 22 14:49:25 BST 1995

Optimising Wavefunctions for Use in Quantum Monte Carlo Calculations

Andrew Williamson
Robinson College

Supervisor: Dr. R.Needs

Cavendish Laboratory (TCM), University of Cambridge, Madingley Road, Cambridge, CB3 0HE, U.K.

• Introduction to Quantum Monte Carlo
  • Variational Quantum Monte Carlo
    • Introduction
    • The Metropolis Algorithm
  • The Trial Wavefunction
  • Diffusion Monte Carlo
  • Current Progress in Optimising Wavefunctions
• Optimising the Trial Wavefunction
  • Motivation for Optimising the Trial Wavefunction
  • Which Part of to Optimise?
  • Optimisation of the Chi Function
    • Choice of parameters
    • Choice of Optimisation Procedure
    • Generating Configurations
  • Results of Optimising the Chi Function
    • Number of Stars required to describe ¸
    • Applying Variance Minimisation to Solid Germanium
    • Optimised Charge density
  • Optimising the Jastrow Factor
    • Choice of Functional Form for new term in the Jastrow Factor
    • Implementation of the new Jastrow Function
    • Results of Optimising the new Jastrow Factor
  • Attempts to Improve further on the Optimisation
    • Removing the Prefactor in
    • Adding a new Function to Chi
  • Conclusions
  • Suggestions for Further Work
• References
• About this document ...