  We describe a modification of the stochastic coupled cluster algorithm that
allows the use of multiple reference determinants. By considering the secondary
references as excitations of the primary reference and using them to change the
acceptance criteria for selection and spawning, we obtain a simple form of
stochastic multireference coupled cluster which preserves the appealing aspects
of the single reference approach. The method is able to successfully describe
strongly correlated molecular systems using few references and low cluster
truncation levels, showing promise as a tool to tackle strong correlation in
more general systems. Moreover, it allows simple and comprehensive control of
the included references and excitors thereof, and this flexibility can be taken
advantage of to gain insight into some of the inner workings of established
electronic structure methods.
