@Override
protected void repulsionN2(Vector3 delta) {
LinLog box = (LinLog) this.box;
boolean is3D = box.is3D();
ParticleBox nodes = box.getSpatialIndex();
Energies energies = box.getEnergies();
Iterator<Object> i = nodes.getParticleIdIterator();
int deg = neighbours.size();
while (i.hasNext()) {
LinLogNodeParticle node = (LinLogNodeParticle) nodes
.getParticle(i.next());
if (node != this) {
delta.set(node.pos.x - pos.x, node.pos.y - pos.y,
is3D ? node.pos.z - pos.z : 0);