Thank you so much for the prompt reply. The code works perfectly. However I

also want to calculate the surface area of each Voronoi tesselation....how

do I write the compute command? It would be very much appreciated if a

sample script is given....

to add a column with surface area data to the voronoi compute use the

"surface group" option:

compute 1 precipitate voronoi/atom surface matrix

where 'matrix' and 'precipitate' are two groups. The surface option

generates an additional column with a surface area for each voronoi

cell (in addition to the volume, which is always computed). The group

given as an argument to the surface option causes only those faces of

the voronoi cell to be counted towards the surface area which are

facing an atom of the given surface group.

In the example above, a precipitate embedded in a matrix, only atoms

at the surface of the precipitate will have non-zero surface are, and

only the outward facing facets of the voronoi cells are counted (the

hull of the precipitate). You can obtain the total surface area of the

precipitate doing a "reduce sum" compute on c_1[3]

If, however, you want the total surface area of _every_ voronoi cell,

just specify "surface all" (using the all group).

Warning, this feature is only lightly tested. Use at your own risk and

report back any success (or failure).

Daniel