Phase space deformation and basis set optimization.

By deforming a given region of phase space---occupied by some unknown eigenfunctions one wishes to find---into a standard, integrable region, effective reductions in basis set size can be achieved. In one-dimensional problems we are able to achieve B/C=1+O(Planck' s constant), where B is the basis set size and C is the number of "converged" eigenfunctions. This result is confirmed by numerical examples, which also indicate exponential convergence as the basis set size is increased.