particle_list = [
            (1, 1, 0, espressopp.Real3D(4.0, 5.0, 5.0), espressopp.Real3D(-1.0, 1.0, 0.0), 1.0, 0),
            (2, 1, 0, espressopp.Real3D(6.0, 5.0, 5.0), espressopp.Real3D(1.0, 1.0, 0.0), 1.0, 0),
            (3, 1, 0, espressopp.Real3D(5.0, 6.2, 5.0), espressopp.Real3D(0.0, 0.0, 0.0), 1.0, 0),
            (4, 1, 0, espressopp.Real3D(3.0, 8.5, 5.0), espressopp.Real3D(0.0, 0.0, 0.0), 1.0, 0),