  In accreting neutron star binaries, matter is channelled by the magnetic
fields from the accretion disc to the poles of neutron stars forming an
accretion mound. We model such mounds by numerically solving the Grad-Shafranov
equation for axisymmetric static MHD equilibria. From our solutions we infer
local distortion of field lines due to the weight of accreted matter. Variation
in mass loading at the accretion disc will alter the shape of the accretion
mound which will also affect the local field distortion. From simulations of
cyclotron resonance scattering features from HMXBs, we conclude that local
field distortion will greatly affect the shape and nature of the CRSF. From
phase resolved spectral analysis one can infer the local field structure and
hence the nature of mass loading of field lines at the accretion disc. We also
study the stability of such mounds by performing MHD simulations using the
PLUTO MHD code. We find that pressure and gravity driven instabilities depend
on the total mass accreted and the nature of mass loading of the field lines.
