In this talk, I will focus on using computational materials methods to shed light on two distinct problems that have intrigued astrochemists and planetary scientists. The first problem deals with the planetary accretion process, where mineral grains coalesce via collisions. Currently, there are no robust models that describe collision dynamics at the nanoscale, especially since the size of grains that initially condense in the solar nebula are nanometric in size. In this regard, I carry out molecular dynamics simulations to examine the extent of grain-coalescence vs grain fragmentation, as well as the extent of volatilization of adsorbed ice (on silicate grains) as a function of relative grain velocity, grain size, and ambient temperature. The second part of the talk will focus on the implementation of Kubo-Greenwood (KG) and Green-Kubo (GK) methods within the DFT workframe to calculate the optical spectra of carbon nanostructures in order to interpret currently unassigned diffuse interstellar bands.
