Monte Carlo hyperspherical description of helium cluster excited states

The J=0 many-body Schrodinger equation for He-4(N) clusters with N=3-10 is solved numerically by combining Monte Carlo methods with the adiabatic hype rspherical approximation. We find ground state and excited state energies f or these systems with an adiabatic separation scheme that reduces the probl em to motion in a one-dimensional effective potential curve as a function o f the hyperspherical radius R. We predict the number of J=0 bound states fo r these clusters, and also the He+HeN-1 elastic scattering lengths up to N= 10. For N=5-10, these are the first such calculations reported. (C) 2000 Am erican Institute of Physics. [S0021-9606(00)01817-1].