I never found such kind of error. However, if I well understand, it seems that you are telling QE to use a trigonal lattice but then you force it to use a lattice with a different symmetry.
ibrav=-5 corresponds to a trigonal lattice, for which a=b=c and the same angle alpha between ANY pair of lattice vectors (alpha=beta=gamma). Probably, the setting you give a=b/=c and beta=gamma/=alpha OVERRIDES any default and you end up with conflicting settings: ibrav=-5 tells QE to use a trigonal lattice and on this basis some symmetries are expected, but based on the input lattice parameters (A, B, C, cosAB, cosAC, cosBC) a lattice with different symmetries is set up. So, try to answer to this question: do you want a trigonal or an hexagonal lattice? In the first case you should change the parameters in input, setting up only A and cosBC, in the second you should use ibrav=4 instead. My guess is that the second answer is the right not, because trying to open your input with Xcrysden nothing is displayed, but if I change ibrav=-5 to ibrav=4 a reasonable crystal shows up! Giovanni > On 12 Mar 2015, at 03:04, John Shin <[email protected]> wrote: > > Hello, > > I am an undergraduate learning how to use Quantum Espresso. I get the > following error when running my input (which I've attached): > > %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% > task # 0 > from set_sym_bl : error # 1 > some problem with symmetries > %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% > > Any help would be greatly appreciated. > > Best, > John Shin > > <Co4(OH)6Cl2_2.pw.in>_______________________________________________ > Pw_forum mailing list > [email protected] > http://pwscf.org/mailman/listinfo/pw_forum -- Giovanni Cantele, PhD CNR-SPIN c/o Dipartimento di Fisica Universita' di Napoli "Federico II" Complesso Universitario M. S. Angelo - Ed. 6 Via Cintia, I-80126, Napoli, Italy e-mail: [email protected] Phone: +39 081 676910 Skype contact: giocan74 ResearcherID: http://www.researcherid.com/rid/A-1951-2009 Web page: http://people.na.infn.it/~cantele _______________________________________________ Pw_forum mailing list [email protected] http://pwscf.org/mailman/listinfo/pw_forum
