$this->isobarCoord[$isobar][$ncoord++] = [
                            $this->getCrossingCoord($neigh[$n3][0], $neigh[$n3][1], $neigh[$n3][2], $ib),
                            $this->getCrossingCoord($neigh[$n4][0], $neigh[$n4][1], $neigh[$n4][2], $ib), ];