<html><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:12pt"><div><span> Dear WIEN2k community,</span></div><div><span>We are working on an insulator bio case, ployalanine amino-acid chain, using the latest version of the WIEN2k code, i.e., WIEN2k 11.1, within PBE-GGA. Our structure contains 48 atoms. The atoms are C, O, N, and H. The lattice type is P with lattice parameters of a=b=13, c=17 angstrom. We have added vacuum along the c-axis, and increase the vacuum from 5 to 25 angstrom. Therefore, c varies from 17+5=22 to 17+25=42 angstrom. The R_MT radii are between 0.67 to 1.2 bohr. We set G_max=20, and RMT*Kmax=4 based on item number 6 of the following link, as indicated in the RMT section of the FAQ:</span></div><div><span>http://www.wien2k.at/reg_user/faq/rmt.html </span></div><div><span>We have used the "in1new 3" flag instead of in1ef to avoid ghost band error to
run_lapw.</span></div><div><span>We select the k-point to be 2x2x1 due to our large lattice parameters which is equivalent to 1 k-point.</span></div><div><span>We plotted energy versus vacuum thickness. We observed that the total energy increases linearly as the vacuum thickness increases. We expected that the total energy asymptotically converged by increasing vacuum thickness to a nearly constant value.</span></div><div><span>But, the energy is not converged even when we increase the vacuum to a large value of 25 angstrom (about 50 bohr!). </span></div><div><br></div><div>Any idea is highly appreciated to overcome this problem so that we can reach to a converged value for the vacuum thickness.</div><div><br></div><div>For your information the :ENEs are pasted below indicating vacuum thicknesses:</div><div>...</div><div>-----------Vacuum=18 bohr----------</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry =
-1143.66370331</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1143.52754252</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1143.36953415</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1143.35063519</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1143.33167823</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1143.32597371</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1143.32132091</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1143.32174685</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1143.32188550</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1143.32197519</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry =
-1143.32198821</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1143.32198492</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1143.32198219</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1143.32198131</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1143.32197955</div><div>-----------Vacuum=20 bohr----------</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1143.20341913</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1143.06185841</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1142.97185748</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1142.91512471</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1142.89150778</div><div>:ENE
: *WARNING** TOTAL ENERGY IN Ry = -1142.88552440</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1142.88070270</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1142.88102994</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1142.88122376</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1142.88131918</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1142.88133048</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1142.88133107</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1142.88132951</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1142.88132839</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry =
-1142.88132703</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1142.88132653</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1142.88132652</div><div>-----------Vacuum=22 bohr----------<br></div><div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1142.73823447</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1142.59540722</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1142.58205832</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1142.47379361</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1142.44173301</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1142.43602112</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1142.43035957</div><div>:ENE
: *WARNING** TOTAL ENERGY IN Ry = -1142.43063581</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1142.43089589</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1142.43097934</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1142.43099282</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1142.43099764</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1142.43099778</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1142.43099678</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1142.43099579</div><div>-----------Vacuum=24 bohr----------<br></div><div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1142.28343926</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry =
-1142.14127406</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1142.21313913</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1142.04180114</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1141.99605423</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1141.99009042</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1141.98464480</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1141.98484180</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1141.98511086</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1141.98520480</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1141.98521697</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry
= -1141.98522315</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1141.98522476</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1141.98522430</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1141.98522338</div><div>...</div><div>-----------Vacuum=30 bohr----------<br></div><div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1140.93575080</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1140.78988094</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1141.29389165</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1140.73672649</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1140.58755964</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry =
-1140.61165126</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1140.60432545</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1140.60055453</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1140.60187927</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1140.60231430</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1140.60316998</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1140.60327053</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1140.60332892</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1140.60334528</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1140.60334602</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry =
-1140.60334714</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1140.60334756</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1140.60334818</div><div>:ENE : *WARNING** TOTAL ENERGY IN Ry = -1140.60334830</div><div>...</div><div>...</div><div>...</div></div></div></div><div> </div><div> </div><div>Sincerely yours,<br>S. Jalali<br>/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/<br>Saeid Jalali Asadabadi,<br>Department of Physics, Faculty of Science,<br>University of Isfahan (UI), Hezar Gerib Avenue,<br>81744 Isfahan, Iran.<br>Phones:<br>Dep. of Phys. :+98-0311-793 2435<br>Office :+98-0311-793 4776<br>Fax No. :+98-0311-793 4800<br>E-mail :<a rel="nofollow" target="_blank"
href="mailto:sjalali@phys.ui.ac.ir">sjalali@phys.ui.ac.ir</a><br> :<a rel="nofollow" target="_blank" href="mailto:sjalali@sci.ui.ac.ir">sjalali@sci.ui.ac.ir</a><br> :<a rel="nofollow" target="_blank" href="mailto:sjalali@mailaps.org">sjalali@mailaps.org</a><br> :<a rel="nofollow" target="_blank" href="mailto:saeid.jalali.asadabadi@gmail.com">saeid.jalali.asadabadi@gmail.com</a><br> :<a rel="nofollow" target="_blank" href="mailto:s_jalali_a@yahoo.com">s_jalali_a@yahoo.com</a><br>Homepage :<a rel="nofollow" target="_blank"
href="http://sci.ui.ac.ir/%7Esjalali">http://sci.ui.ac.ir/~sjalali</a><br>www :<a rel="nofollow" target="_blank" href="http://www.ui.ac.ir/">http://www.ui.ac.ir</a><br>/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/<br><br></div> </div></body></html>