I was reading this paper on QM9 synthetic molecular database and their computed properties. It is stated that All properties were calculated at the B3LYP/6-31G(2df,p) level of quantum chemistry. I was wondering what this 'level of theory' exactly means.

Both Classical Monte Carlo (MC) and Classical Molecular Dynamics (MD) simulations are used to perform simulations of ensembles of molecules. These MC calculations are calculating thermodynamic properties via an ensemble average, while the MD simulations are doing so via a time average. For ergodi...

Some materials have various competing and/or synergistic orders, such as charge density waves and superconducting pairing. Are there signatures of such an interplay between orders that can be seen in the results of ab initio calculations?