1. A QMC Study of the Homogeneous Electron Gas Graham Spink and Richard Needs, TCM, University of Cambridge

2. Homogeneous Electron Gas Electrons move in uniform, positive background potential: Used in Local Density Approximation in DFT: Only one independent parameter, r s, the “typical” distance between electrons. ζ is the spin polarization.

3. Pair Correlation Function

4. Momentum Density Gori-Giorgi and Ziesche, PRB 66, 235116

5. “New” Techniques More accurate Jastrow factor Backflow López Ríos et al., submitted to Phys. Rev. E; @rs=0.5 increases VMC correlation energy by 5% Three-body Jastrow terms Holtzmann et al., Phys. Rev. E 68 046707; @ rs=20, increases VMC correlation energy by over 1% Different treatment of finite-size effects Drummond et al.,

6. PCF Size Convergence

7. PCF with Backflow

10. Pair Correlation Function

11. On top pair density

12. DFT Finite Size Corrections

13. Conclusions and Future Work New techniques in QMC simulations make significant difference to quantities considered With new data we can test recently proposed fitting procedures Now continuing the above at intermediate densities and with DMC

14. Results for PCF PCF (anti-parallel spins) VMC, 162 electrons, r s =3.0, ζ=0.0