A scheme for dealing with the quantum three-body problem is presented to se
parate the rotational degrees of freedom completely from the internal ones.
In this method, the three-body Schrodinger equation is reduced to a system
of coupled partial differential equations, depending only upon three inter
nal variables. For arbitrary total orbital angular momentum l and the parit
y ( -1)(l+lambda) (lambda = 0 or 1), the number of the equations in this sy
stem is l + 1 - lambda. By expanding the wavefunction with respect to a com
plete set of orthonormal basis functions, the system of equations is furthe
r reduced to a system of linear algebraic equations.