Thank you Pietro for the quick reply. Sure, the wurtzite structure I am looking at belongs to the hexagonal crystal system. So the lattice has point group symmetry D_6h (which includes space inversion). But the wurtzite structure (space group 186) has point group symmetry C_6v (it lacks space invesion). It is the latter group that I am refering to and that is correctly used by sym_rho_init_shells and sym_rho_serial. The stars are defined for point group C_6v. However, after symmetrization, the charge density has point group symmetry C_3v, i.e., it is not invariant under C_6v.
What am I missing? Roland On Fri, Mar 13 2026, Pietro Davide Delugas wrote: > Hello > The stars of G vectors depend on the group with all the symmetries > of the lattice. The charge symmetrization is done using the > symmetries of the crystal structure, i.e. the subgroup of the > lattice rotations that do not alter the atomic structure. If the > group and subgroup don' t coincide the charge fourier components do > not necessarily coincide over the whole shells of G vectors. > The symmetrization of rho_G is a bit more complicated because for > each rotation S belonging to the crystal group you need to find the > vector G' which is brought to G by S. > Pietro _______________________________________________________________________________ The Quantum ESPRESSO Foundation stands in solidarity with all civilians worldwide who are victims of terrorism, military aggression, and indiscriminate warfare. -------------------------------------------------------------------------------- Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list [email protected] https://lists.quantum-espresso.org/mailman/listinfo/users
