<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div>Dear community, </div><div><br></div><div>I am puzzled with some non-converging phonon calculations and especially with a very large shift of the Fermi energy in the perturbation step. </div><div>I am doing some calculations on metallic slabs, comparable to Eiguren et al. Phys. Rev. Lett. (2002) vol. 88 (6) 066805 or </div><div>Hofmann et al. New Journal of Physics (2009) vol. 11 (12) 125005. It worked out for several systems, with various thicknesses but now I become </div><div>desperate calculating the phonons of a simple 21layer slab of Cu(111). The vac. is around 2.5nm. The electronic structure looks fine, the relaxation </div><div>is done - but the phonons fail for the Gamma point (only). The Fermi energy shift is unphysically large. The DOS has no resonance nearby. </div><div><br></div><div>So what could be the problem? Any hints would be helpful. </div><div><br></div><div>Thanks Nicki</div><div><br></div><div>following some input/output for the phonons on (away) the Gamma point:</div><div><br></div><div>Input:</div><div><br></div><div><div>&inputph</div><div> reduce_io = .false.</div><div> tr2_ph=1.0d-12,</div><div> prefix='Cu',</div><div> alpha_mix = 0.150</div><div> ldisp=.true.,</div><div> nq1=4, nq2=4, nq3=1</div><div> start_q=1</div><div> last_q=1</div><div> recover = .true.,</div><div> amass(1)=63.546</div><div> outdir="***",</div><div> fildyn='Cu.dyn',</div><div> /</div></div><div><br></div><div>Output Gamma:</div><div><br></div><div>Computing dynamical matrix for.</div><div> q = ( 0.0000000 0.0000000 0.0000000 )</div><div><br></div><div> 7 Sym.Ops. (with q -> -q+G )</div><div>//</div><div>Atomic displacements:</div><div> There are 42 irreducible representations</div><div>//</div><div> Representation # 1 mode # 1</div><div><br></div><div> Self-consistent Calculation</div><div><br></div><div> Pert. # 1: Fermi energy shift (Ry) = -0.1403E+01 -0.8470E-21</div><div> </div><div> iter # 1 total cpu time : 168.5 secs av.it.: 6.1</div><div> thresh= 0.100E-01 alpha_mix = 0.150 |ddv_scf|^2 = 0.277E+00</div><div>//</div><div> Pert. # 1: Fermi energy shift (Ry) = 0.1555E+08 -0.8882E-15</div><div>//</div><div> iter # 100 total cpu time : 2038.3 secs av.it.: 25.3</div><div> thresh= 0.100E-01 alpha_mix = 0.150 |ddv_scf|^2 = 0.313E+15</div><div><br></div><div><br></div><div>And the output for a q-point away from Gamma:</div><div><br></div><div>Computing dynamical matrix for.</div><div> q = ( 0.1443376 0.2500000 0.0000000 )</div><div><br></div><div> 2 Sym.Ops. (no q -> -q+G )</div><div>//</div><div> Atomic displacements:</div><div> There are 63 irreducible representations</div><div>//</div><div>Representation # 1 mode # 1</div><div> </div><div> Self-consistent Calculation</div><div><br></div><div> iter # 1 total cpu time : 1117.1 secs av.it.: 5.8</div><div> thresh= 0.100E-01 alpha_mix = 0.150 |ddv_scf|^2 = 0.315E-04</div><div>//</div><div> iter # 15 total cpu time : 2442.8 secs av.it.: 10.2</div><div> thresh= 0.105E-06 alpha_mix = 0.150 |ddv_scf|^2 = 0.454E-12</div><div><br></div><div><br></div><div><br></div><div>Some info on the self-consistent calculation before:</div><div><br></div><div>occupations='smearing', smearing='methfessel-paxton', degauss=0.01</div><div>ecutwfc = 38.0, ecutrho = 304.0,</div><div>conv_thr = 1.0d-10</div><div>K_POINTS {automatic}: 12 12 1 0 0 0</div><div>nat= 21, ntyp= 1</div><div>CELL_PARAMETERS {hexagonal}</div><div>0.86602540 -0.5000000 0.000000</div><div>0.86602540 0.50000000 0.000000</div><div>0.00000000 0.00000000 25.71450</div><div><br></div><div><br></div><div apple-content-edited="true"> <div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: medium; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: medium; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div><div><br></div><div>-------------------------------------------------------------</div><div>Nicki Frank Hinsche, Dr. rer. nat.</div><div>Institute of physics - Theoretical physics,</div><div>Martin-Luther-University Halle-Wittenberg,</div><div>Von-Seckendorff-Platz 1, Room 1.07<br>D-06120 Halle/Saale, Germany</div><div><div><div>Tel.: ++49 345 5525460</div><div>-------------------------------------------------------------</div></div></div></div></div></div></span></div></span></div></span></div></span></div></div> </div><br></body></html>