I read that, on some papers, conformers were generated by stereoconfiguration of the molecules and from there, they evaluated stability of each stereoisomer in terms of free energy differences between two stereoisomers. Why people illustrated the energy profile of each stereoisomers from their fixed stereoconfiguration, not from global landscape of conformers (conformational distribution) of the molecule and sorting out the conformers by giving plane of symmetry or other methods defining and distinguishing stereoisomers of the molecule? A molecule is always allowed to rotate freely on 3D space and the results of its ability to rotate into a mirror image of its origin is the chirality we are interested in.
Is it possible to tell Gaussian or Spartan to assign stereoconfiguration of each stereoisomers by solely from its generated conformers (conformational distribution) alone without any preconfiguration of its stereoconfiguration? Or I missed a theory that I can’t follow up the general methods on deducting 3D structure of a stereoisomer?