Dear developpers, I wonder if some tool which would permit to recover an approximation of the density matrix from the available charge density is i) already available? ii) in preparation? iii) technically possible/stable/unique ? The idea is, to construct a density matrix in completely different basis, say by least squares fit, from a previous RHO, generated on a sufficiently dense mesh. This would permit to switch to different basis "on the fly", without the need to start from scratch, that may be annoying for big or delicate systems.
Best regards Andrei Postnikov
