title: Conjugate gradient heat bath for ill-conditioned actions.
abstract: We present a method for performing sampling from a Boltzmann distribution of an ill-conditioned quadratic action. This method is based on heat-bath thermalization along a set of conjugate directions, generated via a conjugate-gradient procedure. The resulting scheme outperforms local updates for matrices with very high condition number, since it avoids the slowing down of modes with lower eigenvalue, and has some advantages over the global heat-bath approach, compared to which it is more stable and allows for more freedom in devising case-specific optimizations.
authors.affiliation: Computational Science, Department of Chemistry and Applied Biosciences, ETH Zurich, USI Campus, Via Giuseppe Buffi 13, CH-6900 Lugano, Switzerland. michele.ceriotti@phys.chem.ethz.ch
authors.forename: Michele
authors.initials: M
authors.lastname: Ceriotti
authors.forename: Giovanni
authors.initials: G
authors.lastname: Bussi
authors.forename: Michele
authors.initials: M
authors.lastname: Parrinello