Dielectric susceptibility of dipolar molecular liquids by ab initio molecular dynamics: application to liquid HCl

We study the dielectric susceptibility of liquid hydrogen chloride at a temperature of 313 K using ab initio molecular dynamics evolving in a homogeneous electric field. For an evolution in absence of electric field, the calculated neutron structure factor shows good agreement with the experimental one, supporting the structural properties of our model. We obtain the real and imaginary parts of the dielectric susceptibility as a function of frequency from the evolution of the polarization upon the onset of an electric field. Our simulations give a static dielectric constant of 3.65, in good agreement with the measured value of 3.8.