Hi, Paul I think this two choice wonot make difference for FCC crystal. And I do agree with your last statement . Thanks Paolo and Axel, and Happy new year !
best wishes, hai-ping On Tue, Dec 30, 2008 at 12:56 PM, Paul M. Grant <w2agz at pacbell.net> wrote: > OK, let's get specific...suppose I want to generate a uniformly distributed > set of k-points for the reciprocal lattice of the primitive cell of an fcc > lattice. The output of an scf run (and common sense matrix algebra) tells > me the reciprocal lattice is defined as > > reciprocal axes: (cart. coord. in units 2 pi/a_0) > b(1) = ( 1.000000 0.000000 0.000000 ) > b(2) = ( 0.000000 1.000000 0.000000 ) > b(3) = ( 0.000000 0.000000 1.000000 ) > > OK (again)...I now generate a(n) uniformly distributed grid over the "b" > vectors, and plot the points via xcrysden with PRIMVEC as above and see > that > grid fills the entire basic reciprocal cell (that is, with translation > vector = O). No specification of celldm(1). > > Now, I want to input this grid to an nscf run via K_POINTS...is my grid > "tpiba" or "crystal?" > > BTW, we (this community) owe a huge debt to Paolo and Axel. > > Paul M. Grant, PhD > Principal, W2AGZ Technologies > Visiting Scholar, Applied Physics, Stanford (2005-2008) > EPRI Science Fellow (Retired) > IBM Research Staff Member Emeritus > w2agz at pacbell.net > http://www.w2agz.com > > > > -----Original Message----- > From: pw_forum-bounces at pwscf.org [mailto:pw_forum-bounces at pwscf.org] On > Behalf Of giannozz at democritos.it > Sent: Monday, December 29, 2008 12:29 PM > To: pw_forum at pwscf.org > Subject: Re: [Pw_forum] K_POINTS, tpiba or crystal > > Quoting "Paul M. Grant" <w2agz at pacbell.net>: > > > Frankly, I don't understand what "crystal" means wrt to reciprocal space > > it means "in units of the reciprocal lattice primitive vectors" > > Paolo > > > ---------------------------------------------------------------- > This message was sent using IMP, the Internet Messaging Program. > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > -- Hai-Ping Lan Department of Electronics , Peking University , Bejing, 100871 lanhaiping at gmail.com, hplan at pku.edu.cn -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20081230/a8632caa/attachment.htm
