Implementation of the Linear Method for the optimization of   Jastrow-Feenberg and Backflow Correlations
  We present a fully detailed and highly performing implementation of the Linear Method [J. Toulouse and C. J. Umrigar (2007)] to optimize Jastrow-Feenberg and Backflow Correlations in many-body wave-functions, which are widely used in condensed matter physics. We show that it is possible to implement such optimization scheme performing analytical derivatives of the wave-function with respect to the variational parameters achieving the best possible complexity O(N^3) in the number of particles N. 
M. Motta, G. Bertaina, D. E. Galli, and E. Vitali
cond-mat.str-el