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</o:shapelayout></xml><![endif]--></head><body lang=ZH-CN link="#0563C1" vlink="#954F72" style='word-wrap:break-word;text-justify-trim:punctuation'><div class=WordSection1><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-US>Dear QE-Users,<br><br>I am planning to do some CPMD simulation about iron oxides (Fe2O3, Fe3O4 and FeO) and their reactions with hydrogen at high temperature using cp.x of QE 7.0. My goal is only to try to simulate the reduction process in atomistic scale, and the CPMD trajectory results should sufficiently enough to capture the reduction mechanism while the accuracy of band gap, magnetism is not the focus of my study.<br><br>I know that only ultrasoft potential is acceptable by cp.x. But there are also various kind of ultrasoft pseudopotentials for Fe, O and H, take that for Fe as an example, more than 10 kinds of ultrasoft pseudopotentials are available in the pseudopotential library (http://pseudopotentials.quantum-espresso.org/legacy_tables/original-qe-pp-library/fe):<br> -Fe.pbe-spn-rrkjus_psl.0.2.1.UPF<br> -Fe.pbe-spn-rrkjus_psl.1.0.0.UPF<br> -Fe.pbe-sp-van_mit.UPF<br> - Fe.blyp-sp-van.UPF<br> …<br><br>I am wondering how the choose the best pseudopotentials for the Fe-O-H reaction system. What is the standard to evaluate the performance of a specific pseudopotentials. It seems to be impossible to test all the available potentials one by one.<br><br>Any comment or suggestion will be much appreciated.<br><br>Thanks,<br>Kejiang</span><b><span lang=EN-US style='font-size:11.0pt'><br><br></span></b><span lang=EN-US>-------------------------------------------------<br></span><span lang=EN-US style='font-size:9.0pt'>Dr. Kejiang Li<br>School of Metallurgical and Ecological Engineering,<br>University of Science and Technology Beijing<br>Xueyuan Rd., Haidian District, Beijing 100083, P. R. China</span><span lang=EN-US style='font-size:7.5pt'><br><a href="https://kejiangli.com/" target="_blank">https://kejiangli.com/</a></span><span lang=EN-US style='font-size:9.0pt'><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p></div></body></html>