As shown by [[Baruteau, C. & Masset, F. 2008, Accepted for publication in ApJ]], the non-axisymmetric component of the disk self-gravity can be modeled with an anisotropic pressure tensor. This model multiplies the azimuthal pressure gradient in susbtep1 by an anisotropy coefficient, whose value is calculated with function compute_anisotropic_pressurecoeff in aniso.c. This anisotropy coefficient reads , with the Toomre parameter at the planet's orbital radius, and a parameter that depends only on the softening length to disk scale heigth ratio . The parameter has been calculated only for and . The model can be activated by writing: SelfGravity Z ### and not Yes ZMPlus Yes in your parameter file.