I have a question concerning the box bounds that are printed both to a dump file when using the atom style, and the bounds printed though thermodynamic output when using the lx, ly, or lz attributes.
The simulations I'm running should have the box constantly changing shape. I'm applying a ramped velocity profile to a solid to simulate stretching. The velocity is such that every 1000 timesteps the strain should increment by 0.0001 (the original lengths are around 150 A, so this corresponds to a change in length of 0.015 A every 1000 timesteps.) However, the box bound values look piecewise rather than continuous. For instance: in one simulation from timestep 57000 to 85000 the box length stayed flat at 155.59288 A, then jumped to 156.03231 A. In this case, this corresponds to a jump in strain from 0.0037 to 0.0065. How are the values for lx, ly, and lz calculated? Am I expecting precision that is impossible?