questions about fix ave/chunk density/number

Dear all,

I used fix ave/chunk command to calculate the density number of system consisting of solid and liquid Al. The commands I used are as follow:

compute density_num_1 all chunk/atom bin/1d z lower 0.1

fix 1 all ave/chunk 500 100 50000 density_num_1 density/number file density_number_bin_0.1.txt

After checking the result file, I have two questions:

(1) The result file has four columns: chundID, chunk_coordiante, Ncount, density/number. Since Ncount is the number of atoms in a bin, it should be an integer, but none of Ncounts is integer. All of them are floats.

(2) Since the value of delta in compute chunk/atom is much smaller than interplane spacing of Al crystal(about 4.05), Ncounts of some bins in solid Al should be zero. But I can’t find a bin whose Ncount is zero.

Why these happen? Is there anything wrong in my simulation?

Thanks.

Rui

I don’t think any number should be an integer if you are averaging in time.