See d9fe957. Two problems:
1) that code is present only in one of the three versions of the force calculation (?!)
2) (more serious) the cell might come from another processor, in which case the id it points to might not exist in memory. And even if does it should point to another cell. In the present version this is leading to crashes (which is why I commented it out); this needs to be solved
See d9fe957. Two problems: 1) that code is present only in one of the three versions of the force calculation (?!) 2) (more serious) the cell might come from another processor, in which case the id it points to might not exist in memory. And even if does it should point to another cell. In the present version this is leading to crashes (which is why I commented it out); this needs to be solved