<div dir="ltr">With regard<div>when i want to relax my cell using vc-relax, the convergence is achieved, but I face a strange case. Total energy in the final stage increases as compared to the previous one. for example</div><div>     total energy              =    -247.59002368 Ry<br>     total energy              =    -247.58924945 Ry<br>     total energy              =    -247.59088083 Ry<br>     total energy              =    -247.59072246 Ry<br>     total energy              =    -247.59125131 Ry<br>     total energy              =    -247.59093368 Ry<br>     total energy              =    -247.59106123 Ry<br>     total energy              =    -247.59106093 Ry<br>!    total energy              =    -247.59106127 Ry<br>     The total energy is the sum of the following terms:<br>     total energy              =    -243.69541769 Ry<br>     total energy              =    -247.69824585 Ry<br>     total energy              =    -247.54232603 Ry<br>     total energy              =    -247.63342466 Ry<br>     total energy              =    -247.64259801 Ry<br>     total energy              =    -247.64220374 Ry<br>     total energy              =    -247.64332521 Ry<br>     total energy              =    -247.64332485 Ry<br>     total energy              =    -247.64332190 Ry<br>     total energy              =    -247.64332257 Ry<br>!    total energy              =    -247.64332336 Ry<br>     The total energy is the sum of the following terms:<br>     total energy              =    -242.14907135 Ry<br>     total energy              =    -247.72926932 Ry<br>     total energy              =    -247.70604909 Ry<br>     total energy              =    -247.70434563 Ry<br>     total energy              =    -247.71261404 Ry<br>     total energy              =    -247.71234041 Ry<br>     total energy              =    -247.71242982 Ry<br>     total energy              =    -247.71247293 Ry<br>     total energy              =    -247.71247526 Ry<br>     total energy              =    -247.71247724 Ry<br>     total energy              =    -247.71247892 Ry<br>     total energy              =    -247.71248024 Ry<br>!    total energy              =    -247.71248583 Ry<br>     The total energy is the sum of the following terms:<br>     total energy              =    -249.53370221 Ry<br>     total energy              =    -246.56168268 Ry<br>     total energy              =    -247.80538679 Ry<br>     total energy              =    -248.02150983 Ry<br>     total energy              =    -247.20164339 Ry<br>     total energy              =    -247.72455911 Ry<br>     total energy              =    -247.70953227 Ry<br>     total energy              =    -247.70363286 Ry<br>     total energy              =    -247.72120663 Ry<br>     total energy              =    -247.72079954 Ry<br>     total energy              =    -247.72100110 Ry<br>     total energy              =    -247.72104931 Ry<br>     total energy              =    -247.72105084 Ry<br>     total energy              =    -247.72105154 Ry<br>!    total energy              =    -247.72105458 Ry<br>     The total energy is the sum of the following terms:<br>     total energy              =    -239.19329726 Ry<br>     total energy              =    -248.32657483 Ry<br>     total energy              =    -247.42488015 Ry<br>     total energy              =    -247.75381340 Ry<br>     total energy              =    -247.75556015 Ry<br>     total energy              =    -247.77305174 Ry<br>     total energy              =    -247.73682991 Ry<br>     total energy              =    -247.73404322 Ry<br>     total energy              =    -247.74093764 Ry<br>     total energy              =    -247.73900755 Ry<br>     total energy              =    -247.73918472 Ry<br>     total energy              =    -247.73909016 Ry<br>     total energy              =    -247.73911343 Ry<br>     total energy              =    -247.73880685 Ry<br>     total energy              =    -247.73813372 Ry<br>     total energy              =    -247.73848438 Ry<br>     total energy              =    -247.73847483 Ry<br>     total energy              =    -247.73853098 Ry<br>     total energy              =    -247.73850228 Ry<br>     total energy              =    -247.73851550 Ry<br>     total energy              =    -247.73851422 Ry<br>     total energy              =    -247.73851332 Ry<br>     total energy              =    -247.73851532 Ry<br>!    total energy              =    -247.73851534 Ry<br>     The total energy is the sum of the following terms:<br>     total energy              =    -246.52984283 Ry<br>     total energy              =    -247.77846350 Ry<br>     total energy              =    -247.71603843 Ry<br>     total energy              =    -247.74170092 Ry<br>     total energy              =    -247.74206076 Ry<br>     total energy              =    -247.74149445 Ry<br>     total energy              =    -247.74181677 Ry<br>     total energy              =    -247.74181114 Ry<br>     total energy              =    -247.74181252 Ry<br>     total energy              =    -247.74181182 Ry<br>!    total energy              =    -247.74181230 Ry<br>     The total energy is the sum of the following terms:<br>     total energy              =    -247.48440162 Ry<br>     total energy              =    -247.75010829 Ry<br>     total energy              =    -247.75312836 Ry<br>     total energy              =    -247.74504810 Ry<br>     total energy              =    -247.73757007 Ry<br>     total energy              =    -247.74222517 Ry<br>     total energy              =    -247.74226380 Ry<br>     total energy              =    -247.74204838 Ry<br>     total energy              =    -247.74212675 Ry<br>     total energy              =    -247.74213089 Ry<br>     total energy              =    -247.74214589 Ry<br>     total energy              =    -247.74211558 Ry<br>     total energy              =    -247.74212216 Ry<br>     total energy              =    -247.74212206 Ry<br>     total energy              =    -247.74212212 Ry<br>     total energy              =    -247.74212196 Ry<br>!    total energy              =    -247.74212207 Ry<br>     The total energy is the sum of the following terms:<br>     total energy              =    -247.74046858 Ry<br>     total energy              =    -247.74218262 Ry<br>     total energy              =    -247.74217853 Ry<br>     total energy              =    -247.74218514 Ry<br>     total energy              =    -247.74218681 Ry<br>     total energy              =    -247.74214516 Ry<br>     total energy              =    -247.74205450 Ry<br>     total energy              =    -247.74221990 Ry<br>     total energy              =    -247.74231610 Ry<br>     total energy              =    -247.74196449 Ry<br>     total energy              =    -247.74212672 Ry<br>     total energy              =    -247.74212668 Ry<br>     total energy              =    -247.74212650 Ry<br>!    total energy              =    -247.74212659 Ry<br>     The total energy is the sum of the following terms:<br>     total energy              =    -247.74163500 Ry<br>     total energy              =    -247.74214307 Ry<br>     total energy              =    -247.74214151 Ry<br>     total energy              =    -247.74214230 Ry<br>     total energy              =    -247.74214081 Ry<br>     total energy              =    -247.74208689 Ry<br>     total energy              =    -247.74214068 Ry<br>     total energy              =    -247.74218004 Ry<br>     total energy              =    -247.74208272 Ry<br>     total energy              =    -247.74212669 Ry<br>     total energy              =    -247.74212675 Ry<br>     total energy              =    -247.74212676 Ry<br>     total energy              =    -247.74212677 Ry<br>     total energy              =    -247.74212678 Ry<br>     total energy              =    -247.74212680 Ry<br>     total energy              =    -247.74212678 Ry<br>     total energy              =    -247.74212678 Ry<br>     total energy              =    -247.74212677 Ry<br>!    total energy              =    -247.74212677 Ry<br>     The total energy is the sum of the following terms:<br>     total energy              =    -247.74193429 Ry<br>     total energy              =    -247.74213304 Ry<br>     total energy              =    -247.74213375 Ry<br>     total energy              =    -247.74213303 Ry<br>     total energy              =    -247.74212812 Ry<br>     total energy              =    -247.74212022 Ry<br>     total energy              =    -247.74213951 Ry<br>     total energy              =    -247.74212486 Ry<br>     total energy              =    -247.74212526 Ry<br>     total energy              =    -247.74212682 Ry<br>!    total energy              =    -247.74212684 Ry<br>     The total energy is the sum of the following terms:<br>     total energy              =    -247.74206038 Ry<br>     total energy              =    -247.74212886 Ry<br>     total energy              =    -247.74212907 Ry<br>     total energy              =    -247.74212894 Ry<br>     total energy              =    -247.74212773 Ry<br>     total energy              =    -247.74212378 Ry<br>     total energy              =    -247.74213318 Ry<br>     total energy              =    -247.74212779 Ry<br>     total energy              =    -247.74212660 Ry<br>     total energy              =    -247.74212665 Ry<br>!    total energy              =    -247.74212688 Ry<br>     The total energy is the sum of the following terms:<br>     total energy              =    -247.74211699 Ry<br>     total energy              =    -247.74212717 Ry<br>     total energy              =    -247.74212719 Ry<br>     total energy              =    -247.74212712 Ry<br>     total energy              =    -247.74212680 Ry<br>     total energy              =    -247.74212687 Ry<br>     total energy              =    -247.74212743 Ry<br>     total energy              =    -247.74212745 Ry<br>     total energy              =    -247.74212783 Ry<br>     total energy              =    -247.74212614 Ry<br>!    total energy              =    -247.74212689 Ry<br>     The total energy is the sum of the following terms:<br>     total energy              =    -247.73641383 Ry<br>     total energy              =    -247.73558496 Ry<br>     total energy              =    -247.73571871 Ry<br>     total energy              =    -247.73583115 Ry<br>     total energy              =    -247.73580763 Ry<br>     total energy              =    -247.73581960 Ry<br>     total energy              =    -247.73582095 Ry<br>     total energy              =    -247.73582049 Ry<br>     total energy              =    -247.73582067 Ry<br>!    total energy              =    -247.73582068 Ry<br><br></div><div>As you can see, the final energy is 

-247.73582068 Ry, whereas the total energy at on stage before last scf (

-247.74212689 Ry  ) is minimal, and there is a rise in the last stage (see figure). What can be the cause? What amount of total energy should be selected as energy? Given the uprising, how has convergence been achieved?</div><div><img src="cid:ii_jw7zcaml0" alt="optimize-test1.png" width="497" height="307"><br></div><div><br></div><div>Thanks</div><div><br></div><div><div style="color:rgb(80,0,80)">Seyed Mehrdad Zamzamian</div><div style="color:rgb(80,0,80)">Sharif University of Technology, Tehran, Iran</div><div style="color:rgb(80,0,80)">Energy engineering department</div><div style="color:rgb(80,0,80)">E-mail: <a href="mailto:mehrdad.zamzamian@gmail.com" target="_blank">mehrdad.zamzamian@gmail.com</a></div></div><div><br></div></div>