  Transcorrelated coupled cluster and distinguishable cluster methods are
presented. The Hamiltonian is similarity transformed with a Jastrow factor in
the first quantisation, which results in up to three-body integrals. The
coupled cluster with singles and doubles equations on this transformed
Hamiltonian are formulated and implemented. It is demonstrated that the
resulting methods have a superior basis set convergence and accuracy to the
corresponding conventional and explicitly correlated methods. Additionally,
approximations for three-body integrals are suggested and tested.
