the grid is fine compared to any characteristic length of the geometry. However, the same can be achieved for arbitrary grids, if we take the characteristic length in the just described stratified sampling to be that of the grid.

A different kind of lattice effects has to be taken into account for methods computing a force as a difference in energy for two given geometries. Such methods would typically put a fixed set of loops on each lattice point and add up their energy contributions. Then they would do the same for the same geometry with one object moved in a particular direction. The difference in energy is then proportional to the force component on the moved object in the given direction.

To focus on the net effect, as we do with symmetries (see \[subsubsec:cancellation\]), one typically would use the same set of loops for both geometries. Also, to have for each loop a corresponding shifted loop, the amount the object is moved has to be a multiple of the grid length (in this direction). While doing otherwise would not necessarily yield a bias, doing so significantly improves the convergence speed of this method.

For our purposes, we typically only 