How to smooth an 3D plot

Here I have two Lists. Named as “root1” and “Att”.
I have plotted 3 D plots for them Using “ListPlot3D” command.
The surfaces generated are not smooth.
Is there any algorithm which can make these surfaces smooths ??

Hereby, I am attaching a file regarding this. Kindly find it in attachments.

Thanks…

You can use Interpolation, after converting your triples {x,y,z} into the structure {{x,y},z}:

f = Interpolation[root1 /. {x_Real, y_, z_} :> {{x, y}, z}];
Plot3D[f[x, y], {x, .1, .4}, {y, .1, 9}]

Thanks for response …

But this method is highly error generating…
As you can see that initially it produces the surface

Where as after interpolation it produces the Surface

Which shohs a huge error in Z axis…