“…To achieve our objectives, we shall apply a parametric quintic spline method in the spatial dimension, and use a higher order approximation for fractional derivatives, namely scheme, to increase the efficiency further. It is noted that the parametric quintic spline method has been effective in solving boundary value problems of integer‐order differential equations, and subsequently parametric cubic splines have been applied to fractional differential equations, while the first application of parametric quintic spline to a second‐order fractional sub‐diffusion problem appears in Li and Wong . The fourth‐order fractional sub‐diffusion problem considered in the present work is as follows: where …”