[gmx-users] Box vector shifts number in x and y/z dimension

[xuji]

Hi all:

In gromacs all atoms are in the rectangular or triclinic unit-cell,
and in the codes using shifts with periodic boundary condition.
But why are there only single box vector shifts required in y and z dimensions 
but 2 in x dimension ?

Thanks for any help in advance!
				 
　　　　　　　　xuji
　　　　　　　　xuji at home.ipe.ac.cn
　　　　　　　　　　2008-11-28