  In the presence of an external vertical electric field and strain, it is
evident that 1T${^\prime}$-MoS$_2$ exhibits tilted Dirac bands which are
valley-spin-polarized. Additionally, this material experiences a topological
phase change between a topological insulator and band insulator for a critical
value of the electric field. Using linear response theory, we calculated the
polarization function which is in turn employed to obtain the dielectric
function. This latter quantity is subsequently utilized in calculations to
determine the plasmons dispersion relation, their decay rate and impurity
screening corresponding to various levels of doping, the critical applied
vertical electric field strengths and the spin-orbit coupling gap in
1T${^\prime}$-MoS$_2$ with tilted Dirac bands.
