<html><head></head><body><div class="yahoo-style-wrap" style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:13px;"><div dir="ltr" data-setdir="false"><div><span style="color: rgb(34, 34, 34); font-family: Arial, Helvetica, sans-serif; font-size: small;">Dear all,</span><div style="color: rgb(34, 34, 34); font-family: Arial, Helvetica, sans-serif; font-size: small;"><br></div><div style="color: rgb(34, 34, 34); font-family: Arial, Helvetica, sans-serif; font-size: small;">I'm proceeding with a vc-relax calculation with conv_thr = 10-6 ; energy and force default values. </div><div style="color: rgb(34, 34, 34); font-family: Arial, Helvetica, sans-serif; font-size: small;">The pressure goes to zero but at the last structure the pressure increases to ~ -8 kbar. Since the pressure is negative one must think that the cell is expanding, but what it is observed (checking the cell parameters) is that the cell is contracting.</div><div style="color: rgb(34, 34, 34); font-family: Arial, Helvetica, sans-serif; font-size: small;">Why is this happening? </div><div style="color: rgb(34, 34, 34); font-family: Arial, Helvetica, sans-serif; font-size: small;"><br></div><div style="color: rgb(34, 34, 34); font-family: Arial, Helvetica, sans-serif; font-size: small;">Thank you in advance,</div><div style="color: rgb(34, 34, 34); font-family: Arial, Helvetica, sans-serif; font-size: small;"><br></div><div style="color: rgb(34, 34, 34); font-family: Arial, Helvetica, sans-serif; font-size: small;">Dr. Inna Nangoi</div></div><div style="color: rgb(34, 34, 34); font-family: Arial, Helvetica, sans-serif; font-size: small;" dir="ltr" data-setdir="false"><div><div dir="ltr" style="color: rgb(34, 34, 34); font-family: Arial, Helvetica, sans-serif; font-size: small;">Grupo de Físico-Química de Sólidos e Interfaces (GFQSI)</div><div dir="ltr" style="color: rgb(34, 34, 34); font-family: Arial, Helvetica, sans-serif; font-size: small;" data-setdir="false"><div><div dir="ltr" style="color: rgb(34, 34, 34); font-family: Arial, Helvetica, sans-serif; font-size: small;"><a href="http://www.ufjf.br/gfqsi/" data-saferedirecturl="https://www.google.com/url?q=http://www.ufjf.br/gfqsi/&source=gmail&ust=1573306704451000&usg=AFQjCNENfyH0JCyJQ1eqy6d3SAOP2SATMg" style="color: rgb(17, 85, 204);" rel="nofollow" target="_blank">http://www.ufjf.br/gfqsi/</a></div></div>Universidade Federal de Juiz de Fora - UFJF<br></div></div></div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">INPUT:</div><div dir="ltr" data-setdir="false"><div><div> /</div><div> &SYSTEM</div><div> ibrav = 0,</div><div> celldm(1) = 1.8897265,</div><div> nat = 408,</div><div> ntyp = 2,</div><div> ecutwfc = 40 ,</div><div> ecutrho = 400 ,</div><div> /</div><div> &ELECTRONS</div><div> conv_thr = 1.D-6 ,</div><div> /</div><div> &IONS</div><div> /</div><div> &CELL</div><div> /</div><div>CELL_PARAMETERS cubic</div><div> 16.467196779 0.003155548 0.004141842</div><div> 0.003137055 16.453425288 -0.000761157</div><div> 0.004171643 -0.000775474 16.446571996</div><div>ATOMIC_SPECIES</div><div> O 16.00000 O.pbe-n-kjpaw_psl.1.0.0.UPF</div><div> H 1.01000 H.pbe-kjpaw_psl.1.0.0.UPF</div><div>ATOMIC_POSITIONS angstrom</div><div>O 9.321137481 14.266560377 9.327818241</div><div>H 9.682105309 14.676153052 8.481823531</div><div>H 10.049781829 14.333756337 10.015860139</div><div>O 11.166283791 6.044399971 2.975926238</div><div dir="ltr" data-setdir="false"><div><div style="color: rgb(0, 0, 0); font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;">.</div><div style="color: rgb(0, 0, 0); font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;">. </div><div style="color: rgb(0, 0, 0); font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;">. </div><div dir="ltr" data-setdir="false" style="color: rgb(0, 0, 0); font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;">K_POINTS gamma <div></div></div><div><br></div></div><br></div></div><br></div><div dir="ltr" data-setdir="false">OUTPUT: </div><div dir="ltr" data-setdir="false"><br></div></div><div dir="ltr" data-setdir="false"><div><div dir="ltr" data-setdir="false"><div><div> End of BFGS Geometry Optimization</div><div><br></div><div> Final enthalpy = -5995.1370960771 Ry</div><div>Begin final coordinates</div><div> new unit-cell volume = 28794.22023 a.u.^3 ( 4266.86316 Ang^3 )</div><div> density = 0.95375 g/cm^3</div><div><br></div><div>CELL_PARAMETERS (alat= 1.88972650)</div><div> 16.229014053 0.002449560 0.005745845</div><div> 0.002429308 16.219588894 0.000479082</div><div> 0.005772101 0.000461059 16.209758644</div><div><br></div><div>ATOMIC_POSITIONS (angstrom)</div><div>O 9.180431407 14.143089383 9.191719262</div><div>H 9.561522937 14.567241497 8.352842759</div><div>H 9.908913197 14.170313644 9.891402550</div><div>O 11.026600724 5.996092777 2.933422632</div><div>H 11.877618746 6.446014321 2.622523705</div><div>H 10.719968316 6.437111173 3.792164500</div><div>O 5.141235135 15.134646177 1.987199104</div><div>H 4.933636936 15.342422258 1.017207703</div><div>H 5.853001846 14.414601411 1.987420436</div><div dir="ltr" data-setdir="false"><div><div style="color: rgb(0, 0, 0); font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;"> .</div><div style="color: rgb(0, 0, 0); font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;"> . </div><div style="color: rgb(0, 0, 0); font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;"> . </div><div style="color: rgb(0, 0, 0); font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;" dir="ltr" data-setdir="false"> <div><div>H 13.338033020 5.155154854 13.251553812</div><div>O 11.079195321 9.183121298 6.146092164</div><div>H 10.379755422 9.912994593 6.143398011</div><div>H 11.912644022 9.559263869 5.711046728</div><div>End final coordinates</div><div> .<br></div></div></div></div></div></div></div><div> . </div><div> . </div><div> Total force = 0.008044 Total SCF correction = 0.000070</div><div><br></div><div><br></div><div> Computing stress (Cartesian axis) and pressure</div><div><br></div><div><br></div><div> negative rho (up, down): 9.616E-06 0.000E+00</div><div> total stress (Ry/bohr**3) (kbar) P= -8.32</div><div> -0.00005717 -0.00000010 -0.00000025 -8.41 -0.01 -0.04</div><div> -0.00000010 -0.00005654 0.00000006 -0.01 -8.32 0.01</div><div> -0.00000025 0.00000006 -0.00005604 -0.04 0.01 -8.24</div><div><br></div><div><br></div><div dir="ltr" data-setdir="false"><div><div> total stress (Ry/bohr**3) (kbar) P= -12.00</div><div> total stress (Ry/bohr**3) (kbar) P= -10.74</div><div> total stress (Ry/bohr**3) (kbar) P= -7.11</div><div> total stress (Ry/bohr**3) (kbar) P= -2.92</div><div> total stress (Ry/bohr**3) (kbar) P= 0.65</div><div> total stress (Ry/bohr**3) (kbar) P= 0.70</div><div> total stress (Ry/bohr**3) (kbar) P= 0.30</div><div> total stress (Ry/bohr**3) (kbar) P= 0.08</div><div> total stress (Ry/bohr**3) (kbar) P= -0.19</div><div> total stress (Ry/bohr**3) (kbar) P= -0.43</div><div> total stress (Ry/bohr**3) (kbar) P= -0.58</div><div> total stress (Ry/bohr**3) (kbar) P= -0.40</div><div> total stress (Ry/bohr**3) (kbar) P= -0.06</div><div> total stress (Ry/bohr**3) (kbar) P= 0.25</div><div> total stress (Ry/bohr**3) (kbar) P= 0.42</div><div> total stress (Ry/bohr**3) (kbar) P= 0.43</div><div> total stress (Ry/bohr**3) (kbar) P= 0.26</div><div> total stress (Ry/bohr**3) (kbar) P= -0.03</div><div> total stress (Ry/bohr**3) (kbar) P= -0.29</div><div> total stress (Ry/bohr**3) (kbar) P= -0.53</div><div> total stress (Ry/bohr**3) (kbar) P= -0.37</div><div> total stress (Ry/bohr**3) (kbar) P= -0.19</div><div> total stress (Ry/bohr**3) (kbar) P= 0.18</div><div> total stress (Ry/bohr**3) (kbar) P= 0.36</div><div> total stress (Ry/bohr**3) (kbar) P= 0.50</div><div> total stress (Ry/bohr**3) (kbar) P= 0.33</div><div> total stress (Ry/bohr**3) (kbar) P= 0.06</div><div> total stress (Ry/bohr**3) (kbar) P= -0.09</div><div> total stress (Ry/bohr**3) (kbar) P= -0.34</div><div> total stress (Ry/bohr**3) (kbar) P= -0.28</div><div> total stress (Ry/bohr**3) (kbar) P= -0.10</div><div> total stress (Ry/bohr**3) (kbar) P= 0.03</div><div> total stress (Ry/bohr**3) (kbar) P= 0.25</div><div> total stress (Ry/bohr**3) (kbar) P= 0.25</div><div> total stress (Ry/bohr**3) (kbar) P= -8.32</div></div><br></div><div><br></div><div><br></div></div><br></div></div></body></html>