Many models in scientific computing involve long-range particle interactions, for example the Coulomb interaction of electrically charged particles. To address the cost of computing these interactions in large-scale computations, we present two fast summation methods based on barycentric Lagrange interpolation, a treecode (BLTC) and a fast multipole method where the interaction lists are formed by dual tree traversal (BLDTT). The methods are kernel-independent and a distributed memory implementation on multiple GPUs has been developed. The performance of the BLTC and BLDTT is demonstrated, and an application to the electrostatics of solvated biomolecules is presented. Speaker(s): Robert Krasny (University of Michigan)