This article explores a diabatic formulation of electronically adiabatic quantum reactive scattering problems. In particular, a diabatic approach to the close-coupling wave packet method is developed which allows us to perform, efficiently, accurate calculations using natural coordinate systems for both the reactant and product configurations. The efficiency and accuracy of the method are investigated in terms of the size of the basis sets, as well as in terms of the symmetry of the diabatic coupling and demonstrated for a model H + H-2 collinear reaction. Extension of the method to three-dimensional problems is discussed.