Dear Giuseppe, Thanks for your kind explanation.
As per your suggestion, it might be better to do 'vc-relax'/'relax' only with pw.x, while do CPMD only with cp.x. But we should try to keep the parameters (such as, nspin, tot_magnetization, lda_plus_u, Hubbard_U(i), degauss, smearing, ...) being the same for the same materials while dong 'vc-relax'/'relax' with pw.x and CPMD with cp.x. I will do more test and let you know if any progress/problem. Thanks. Kejiang -----邮件原件----- 发件人: [email protected] <[email protected]> 代表 Giuseppe Mattioli 发送时间: 2022年4月7日 18:22 收件人: [email protected] 主题: Re: [QE-users] Difference between pw.x and cp.x for relax, ve-relax calculation Dear Kejiang As a very general rule, partially depending on the history of the codes included in the QE distribution, pw.x is the "engine" for electronic structure calculations (including geometry and cell optimizations, but also Born-Oppenheimer MD simulations), and cp.x the "engine" for Car-Parrinello ab initio molecular dynamics simulations. A very high degree of interoperability between the two codes has been achieved in more recent years, but as a useful rule of thumb it is still sensible to perform your calculations using the designated code. Regarding the main parameters, of course using the same pseudopotentials with the same ecutwfc and ecutrho is a good starting point, but there are tips and tricks that depend on your actual setup. HTH Giuseppe Quoting [email protected]: > Dear QE-Users, > > In QE 7.0, I noticed that the calculation choice for cp.x can also be > 'relax', 'vc-relax', 'scf', and 'nscf' which are the key functions of pw.x. > But the other parameters in cp.x are far less than the pw.x, for > instance, it is known that K point cannot be set in cp.x. > > Could anyone help to explain the difference between pw.x and cp.x for > 'relax', 've-relax' calculation. > > Because I am trying to do some CPMD simulation which can only be done > with cp.x, I hope to use cp.x for 'relax' and 'vc-relax' calculation > to keep the consistence of parameters in the whole process. > > Any comments or suggestions will be much appreciated. > > All the best, > Kejiang > > ------------------------------------------------- > Dr. Kejiang Li > School of Metallurgical and Ecological Engineering, University of > Science and Technology Beijing Xueyuan Rd., Haidian District, Beijing > 100083, P. R. China https://kejiangli.com/ GIUSEPPE MATTIOLI CNR - ISTITUTO DI STRUTTURA DELLA MATERIA Via Salaria Km 29,300 - C.P. 10 I-00015 - Monterotondo Scalo (RM) Mob (*preferred*) +39 373 7305625 Tel + 39 06 90672342 - Fax +39 06 90672316 E-mail: <[email protected]> _______________________________________________ The Quantum ESPRESSO community stands by the Ukrainian people and expresses its concerns about the devastating effects that the Russian military offensive has on their country and on the free and peaceful scientific, cultural, and economic cooperation amongst peoples _______________________________________________ Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list [email protected] https://lists.quantum-espresso.org/mailman/listinfo/users _______________________________________________ The Quantum ESPRESSO community stands by the Ukrainian people and expresses its concerns about the devastating effects that the Russian military offensive has on their country and on the free and peaceful scientific, cultural, and economic cooperation amongst peoples _______________________________________________ Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list [email protected] https://lists.quantum-espresso.org/mailman/listinfo/users
