Linear magnetic susceptibility of anisotropic superconductors of cuboidal shape

A simplified model of anisotropic magnetic susceptibility in the Meissner-London vortex-free state of cuboidal superconducting samples is presented. Using this model, precision measurements of the magnetic response in three perpendicular directions of a magnetic field with respect to primary crystal axes, can be used to extract the components of the London penetration depth, thus enabling the evaluation of the general superfluid density tensor, which is needed in the analysis of the superconducting gap structure.