Dear Li Niu: Isotopes of one given element have the same chemical properties that is to say the same electronic structure, so the electrons of the isotopes are the same from each other, and the only thing different is the MASS of the atom.So you only need to give the corresponding mass of the isotopic atom which you want to substitute. In addition, are you calculating critical superconducting temperature? If you are, and your system is compound, then you can calculate the isotope effect of every type of atom by this substitution, the formula of which is: -d(logTc)/d(logm), you can refer to the paper for details: Matteo Calandra and Francesco Mauri, "Theoretical Explanation of Superconductivity in C6Ca" PRL 95 237002(2005)
Yours Sincerely L.F.Huang > Date: Thu, 18 Dec 2008 14:58:29 +0800 (CST) > From: li niu > Subject: [Pw_forum] calculation about isotope substitution > To: pw_forum at pwscf.org > Message-ID: > Content-Type: text/plain; charset="utf-8" > > Dear Pwscf user, > ? > I'm a PWSCF user from China. I want to calculate the influence of isotope > substitution on the phonon modes. But I don?t know how to implement it?Any > help will be appreciated. > ? > So many thanks in advance! > ? > Best Regards, > > Li Niu > Ph.D. Candidate, > Center for Composite Materials, > Harbin Institute of Technology, > Harbin, Heilongjiang, 150080, China ------ ====================================================================== L.F.Huang(???) lfhuang at theory.issp.ac.cn ====================================================================== Add: Research Laboratory for Computational Materials Sciences, Instutue of Solid State Physics,the Chinese Academy of Sciences, P.O.Box 1129, Hefei 230031, P.R.China Tel: 86-551-5591464-328(office) Fax: 86-551-5591434 Web: http://theory.issp.ac.cn (website of our theory group) http://www.issp.ac.cn (website of our institute) ====================================================================== -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20081218/d99ac6e1/attachment.htm
