Dear users I have get the difference gradients for 3N coordinates but I want to change them to the difference gradients for Z-maxtrix variables. Here is the dgrad for 3N SA-MC DIFF. GRADIENT FOR STATES 2.1 - 1.1 Atom dE/dx dE/dy dE/dz 1 -0.000000002 -0.006200955 0.000000000 2 0.000000002 0.006200955 0.000000000 Thanks a lot !