Exploring the Bulk Phase Properties and Structural Properties for CO2 and so2 Via First Principles Calculations

To capture the underlying chemistry and physics of a system, it is necessary to accurately describe the intermolecular interactions such as repulsion, polarization, hydrogen bonding, and van der Waals interactions. Among these interactions, van der Waals (dispersion) interactions are weak in nature as compared to covalent bonds and hydrogen bonding, but govern thermophysical properties of condensed phase systems. CO₂ and SO₂ molecules have numerous industrial applications and predicting their condensed phase and microscopic properties by first principles calculations can be very helpful in the designing of the processes. The latest density functionals can predict with reasonable accuracy the minima and binding energy for dimers or small cluster of molecules, however, their performance for condensed phase is somewhat uncertain. The aim of the present work is to assess the accuracy of Kohn-Sham density functional theory (DFT) by using different functionals that can account for predicting the bulk phase properties and structural properties for CO₂ and SO₂ via first principles Monte Carlo simulations. In this work, we have investigated the accuracy of dispersion corrected GGA (BLYP, PBE), hybrid (PBE0) meta-hybrid GGA (MO6-2X) functional and nonlocal van der Waals functionals.