<html>Dear Naval,<br /><br />You sould look at the output movie created by the NEB (coordinates.axsf).<br />Does it looks like it is the correct chemical reaction?<br />Is you simulation cell big enough to ensure that the H position is sufficiently far away from the CO2 molecule to not interact with it and to have 0 forces?<br />You should probably add some intermediate images and force a climbing image (CI_scheme= 'auto')<br /><br />Regards,<br /><br />Le Vendredi, Janvier 13, 2023 05:40 CET, naval singh via users <users@lists.quantum-espresso.org> a écrit:<br /> <blockquote type="cite" cite="251362480.492525.1673584845848@mail.yahoo.com"> </blockquote><div class="ydp730fce64yahoo-style-wrap" style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:16px;"><div id="ydp730fce64yiv1362079554"><div><div style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:16px;" class="ydp730fce64yiv1362079554yahoo-style-wrap"><div dir="ltr">Dear all ,</div><div dir="ltr">i am trying to protonate hydrogen on the adsorbed co2 and to form cooh and ocho and computing energy barrier for protonation using neb calculation but the barrier is turning out to be 0 ev but as we all know activation barrier cant be zero do suggest some solution</div><div dir="ltr">thanks in advance </div></div></div></div></div><br /><br /><br />-----------------------------------------------------------------------------------------<br />Antoine Jay LAAS-CNRS<br /><a data-jsarwt="1" data-usg="AOvVaw2dma9pkaRKEmU1HxOZr2tk" data-ved="2ahUKEwjf2pi-4aL0AhUBxoUKHSP4AQ4QFnoECBMQAQ" href="https://www.laas.fr/public/fr/m3">ajay@laas.fr</a> 7, Avenue du Colonel Roche <br />(+33)5 61 33 79 56 BP 54200, 31031 Toulouse cedex 4 <br />Equipe<strong> M^3 M</strong>odélisation <strong>M</strong>ulti-niveaux des <strong>M</strong>atériaux <br />------------------------------------------------------------------------------------------</html>