2]R / R having the dimension of an energy and containing Planck's constant and (therefore) appropriately defined quantum potential.

However, this approach is not appropriate for time-of-flight neutron diffraction for which the measured time of flight t is related to d-spacing d as; t = (2 mL/ h)d sin [theta] where m = neutron mass L = neutron flight path h = Planck's constant [theta] = scattering angle and the time resolution dt/t is given by: dt/t = (dL/L) + (cot [theta]) d[theta].

1/2]] (1) where m, e, and h are the electron mass, charge on an electron, and Planck's constant, respectively, and [phi], s, V are the height of tunnelling barrier, the barrier's width and the voltage applied across the barrier, respectively.