On Monday 21 November 2005 15:26, Sergey Lisenkov wrote: > from coset : error # 0 > The order of the group is not a multiple of that of the subgroup > > What does it mean?
it means that the symmetry group of your system is not a group. The algorithm that finds the point group symmetries of the crystal uses a threshold to decide whether the symmetry is there or not. Apparently you found a set of coordinates and of lattice vectors for which seven candidate symmetry operations pass the test, the eight (inversion) fails. Possible options: - disable fractionary translations (set fractional_translations = .false. in PW/sgam_at.f90): the six operations in addition to identity have nonzero fractionary translations - change the threshold (accep in PW/eqvect.f90) - use option 'nosym' to disable symmetry (read carefully what it does) - change a little bit atomic positions so as to break symmetry for good - best of all: find a better algorithm to determine the symmetry ... By the way: what should be the symmetry of this system? Paolo -- Paolo Giannozzi e-mail: giannozz at nest.sns.it Scuola Normale Superiore Phone: +39/050-509876, Fax:-563513 Piazza dei Cavalieri 7 I-56126 Pisa, Italy
