Dear Christian, I spend the last two weeks testing this setting (nat_todo=16). My system contains more than 200 atom and was optimized until the forces on all the atoms were less than 0.02 eV/A. Then, I wanted to calculate the zero-point-energy (zpe) correction for the adsorbed molecule (benzene derivative) using ph.x. Unfortunately, I obtained a lot of imaginary frequencies (at the beginning of dynamical matrix in the ph.out file ): freq ( 1) = -98.010682 [THz] = -3269.284435 [cm-1] freq ( 2) = -95.651863 [THz] = -3190.602722 [cm-1] freq ( 3) = -72.672472 [THz] = -2424.092724 [cm-1] freq ( 4) = -71.325508 [THz] = -2379.162841 [cm-1] freq ( 5) = -66.443681 [THz] = -2216.322637 [cm-1] freq ( 6) = -63.174512 [THz] = -2107.274901 [cm-1] freq ( 7) = -61.771254 [THz] = -2060.467247 [cm-1] freq ( 8) = -59.520061 [THz] = -1985.375532 [cm-1] ... ... Then, when I wanted to calculate the dynamical matrix, the program (dynmat.x) stuck on attemption the asr calculation. .... Acoustic Sum Rule: || Z*(ASR) - Z*(orig)|| = 0.000000E+00 The input file for dynmat.x is: &input fildyn = 'benz_surf.dyn' asr = 'zero-dim' / If this setting will work properly, it would be very helpful for all these QE users working on the theoretical catalysis. Best, Tomasz Krol Cracow University of Technology W dniu 2019-11-05 17:42:13 użytkownik Hari Paudyal <[email protected]> napisał: Hi Christian, nat_todo can be used to choose the subset of atoms to be used in the linear response calculation. Please have a look if that is under your interest. Best, Hari Paudyal SUNY, Binghamton On Tue, Nov 5, 2019 at 11:26 AM Christian helman <[email protected]> wrote: Hi I just calculate an interface between two compounds. No problem and results are as expected. however I would like to calculate the phonons at the interface (even more electron -phonon coupling but let's start with just phonons). Since my unit cell is huge, my question is : is there any way to calculate the phonons "only at the interface" by allowing to move the interface atoms ?? something like "selective dynamics" Thanks in advance -- Dr. Christian Helman Departamento de Neutrones y Reactores Centro Atómico Bariloche -CNEA Ezequiel Bustillos 9,500 Km - CP 8400 San Carlos de Bariloche Provincia de Rio Negro, Argentina Tel:++54-294-444-5100 int 5308 _______________________________________________ Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso) users mailing list [email protected] https://lists.quantum-espresso.org/mailman/listinfo/users
_______________________________________________ Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso) users mailing list [email protected] https://lists.quantum-espresso.org/mailman/listinfo/users
