Thanks for the recommendation. I have performed the calculation with the iverbosity set to 1. It will take me a while to parse it and understand the output, but if I can figure out the relationships, I will attempt to code the ordering into the application.
Cheers Jeff Mullen North Carolina State University Dal Corso Andrea wrote: > >It is an interesting idea. I think it is possible to make the >symmetry classification of the displacements patterns with the same >routine that makes the symmetry classification of the eigenvectors >of the dynamical matrix. Presently, this is not done. You can >code this feature yourself or just use iverbosity=1. With this option >the code writes the displacement patterns and you can >check their symmetry. > >Andrea > > > > > >>Cheers >>Jeff >> >> >> >>e kb wrote: >> >> >> >>>Dear Jeff, >>>I am definitely not an expert on the topic but I'd like to understand >>>your question better. >>> >>> Mode symmetry, D_6h(6/mmm) point group: >>> >>> omega( 1 - 1) = -37.4 [cm-1] --> A_2u I >>> omega( 2 - 3) = -33.9 [cm-1] --> E_1u I >>> omega( 4 - 4) = 863.3 [cm-1] --> B_2g >>> omega( 5 - 6) = 1336.0 [cm-1] --> E_2g >>> >>>So you have the irr. representations and the values for omega (values >>>are printed with higher precision in the previous part after >>>diagonalization as you reported). What exactly do you want to know >>>more (that you cannot check from a book on group theory) ? >>> >>>Emine Kucukbenli, grad. student, SISSA, Italy. >>> >>>--- On *Tue, 3/10/09, Jeffrey Mullen /<jtmullen at ncsu.edu>/* wrote: >>> >>> From: Jeffrey Mullen <jtmullen at ncsu.edu> >>> Subject: [Pw_forum] Phonon branch enumeration >>> To: pw_forum at pwscf.org >>> Date: Tuesday, March 10, 2009, 2:34 AM >>> >>>Greetings >>> >>>I am testing electron-phonon interaction calculations with graphene and >>>have encountered a problem enumerating the resulting phonon branches. >>>When I run the ph.x calculation at the q(0 0 0), the code calculates 4 >>>representations: >>> >>> Representation # 1 modes # 1 2 >>> Representation # 2 mode # 3 >>> Representation # 3 mode # 4 >>> Representation # 4 modes # 5 6 >>> >>> >>>When the values for omega are calculated, the results are: >>> >>>************************************************************************** >>> omega( 1) = -1.119851 [THz] = -37.354451 [cm-1] >>> omega( 2) = -1.016557 [THz] = -33.908905 >>>[cm-1] >>> omega( 3) = -1.016557 [THz] = -33.908905 [cm-1] >>> omega( 4) = 25.882237 [THz] = 863.344237 [cm-1] >>> omega( 5) = 40.051667 [THz] = 1335.988701 [cm-1] >>> omega( 6) = 40.051667 [THz] = 1335.988701 [cm-1] >>>************************************************************************** >>> >>> >>>with the following mode symmetries: >>> >>> Mode symmetry, D_6h(6/mmm) point group: >>> >>> omega( 1 - 1) = -37.4 [cm-1] --> A_2u I >>> omega( 2 - 3) = -33.9 [cm-1] --> E_1u I >>> omega( 4 - 4) = 863.3 [cm-1] --> B_2g >>> omega( 5 - 6) = 1336.0 [cm-1] --> E_2g R >>> >>> >>>My question is one of ordering. How do I extract which omega(##) >>>corresponds to which representation/mode? >>> >>>Thanks >>>Jeff Mullen >>>North Carolina State >>>University >>> >>>_______________________________________________ >>>Pw_forum mailing list >>>Pw_forum at pwscf.org >>>http://www.democritos.it/mailman/listinfo/pw_forum >>> >>> >>> >>>------------------------------------------------------------------------ >>> >>>_______________________________________________ >>>Pw_forum mailing list >>>Pw_forum at pwscf.org >>>http://www.democritos.it/mailman/listinfo/pw_forum >>> >>> >>> >>> >>_______________________________________________ >>Pw_forum mailing list >>Pw_forum at pwscf.org >>http://www.democritos.it/mailman/listinfo/pw_forum >> >>
