[ESPResSo] position folded in the code?

[BIN ZHANG]

Hi, there:

I have been reading the code of Espresso, and get confused about how the positions for each particle is stored. What exactly are the variables stored in the part[i].r.p[0-2]? are these folded positions around the pbc box? or real positions in 3d space?

From the function centermass() in statistics.c, it seems to me that they are folded positions, since unfold_position() are called explicitly. Also, the function in domain decomposition: dd_exchange_and_sort_particles(), kind of support this. 

If this were true, I would expect to call unfold_position() before any update of position in integrate.c. However, I do not see any folding, unfolding there. 

Could you give me any hint or point to me the correct file I should be looking at?

Thanks very much,

Bin