How to create a .mat file of the following example?

I have a data in the following format: (i, j, k, val) where i, j, k are variables and val is the corresponding data at i, j, k values. I want to save the .mat file in the (i, j, k, val) format, so that my .mat files looks like:

(0, 0, 0, 1.5E-02)

(0, 0, 1, 2.5E-05)

...........................

(5, 5, 5, 4.5 E-05)

How can I create this type of .mat file? I would appreciate any help on this.

Actually these data are the octant of a 11 by 11 by 11 matrix (isotropic cubic matrix). I would like to have a full-size matrix using the symmetry property of the octant. I want to save the octant data in a .mat file so that I could iterate over the 8 possibilities to make a full size matrix.