Solvers

x-Crossing Approximation

Implementation of the Non-Crossing and One-Crossing Approximation methods, standard impurity solvers for strongly-correlated problems.

GF-CCSD

Implementation of the Green’s function coupled cluster singles and doubles impurity solver.

Counterterm Solver

Hybrid Hamiltonian-diagrammatic quantum impurity solver that augments diagrammatic expansions with a small auxiliary bath for high-precision, rapidly converging solutions.