"Carcass" wavefunctions in many-particle variational calculations

We present a refined procedure for many-particle variational calculations. The procedure is based on the use of "carcass" trial wave-functions which reach a maximum for a definite spatial configuration of the particles. This configuration is given by a system of variational vectors. Using the example of three- and four-particle calculations we show that this procedure is capable of improving considerably the convergence of the variational calculations. Despite the more complex form of the matrix elements this procedure is, in many cases, more economical than the analogous calculations with non-carcass wavefunctions.