Approximate density matrices for spherical metal clusters

On the sole basis of the knowledge of the expectation values of several phy sical observables, an inferred density matrix for spherical alkali-metal cl usters is obtained. No explicit knowledge of any Hamiltonian model is assum ed. A combination of information theory with the pseudoinverse variational formalism is employed, and densities for spherical Na clusters are obtained . [S0163-1829(99)09127-4].