which is a mapping of the initial configuration κ κ 0 ( B ) onto the current configuration κ κ t ( B ) , giving a geometrical correspondence between them, i.e. giving the position vector x = x i e i that a particle X , with a position vector X in the undeformed or reference configuration κ κ 0 ( B ) , will occupy in the current or deformed configuration κ κ t ( B ) at time t . The components x i are called the spatial coordinates.