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<body>Dear Eyvaz and Paolo:<BR>
Thanks for your kind reply! With your advice, I get the results of interatomic force constants in real space at gamma point.<BR>> Hi,<BR>> <BR>> --- mashangyi <shang.yi@hotmail.com> wrote:<BR>> <BR>> > Dear all: I encounter a problem when I use the<BR>> > q2r.x transform the dynamical matrix of gamma point<BR>> > to interatomic force constants in real space. The<BR>> > system in my calculation is a Si-supercell composed<BR>> > of 64 Si atoms. I want to get some properties of it,<BR>> > like phdos, vibrational energy, entropy and so on.<BR>> > Following example02 and 06 indication, I calculate<BR>> > the dynamical matrix at the gamma point of the<BR>> > supercell after scf calculation( scf use 2x2x2<BR>> > k_points). When I call q2r.x to calculate IFC's in<BR>> > real space, it complains the follow<BR>> ><BR>> errors:+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++<BR>> > transforming Si-bulk.q2r.in C(q) => C(R)...forrtl:<BR>> > severe (19): invalid reference to variable in<BR>> > NAMELIST input, unit 5, file stdin, line 5, position<BR>> <BR>> There is very clean indication what is wrong: you<BR>> specified a parameter which does not exist in<BR>> NAMELIST.<BR>> <BR>> > and q2r.x input-file:<BR>> > &input fildyn = 'si-bulk.dynG' zasr = 'simple'<BR>> > flfrc = 'si-bulk.fc' nr1=2, nr2=2, nr3=2 nfile = 1<BR>> <BR>> > filin = 'si-bulk.dynG'/<BR>> <BR>> There is no keyword "filin" in NAMELIST. That is your<BR>> problem, so, remove this line.<BR>> <BR>> Besides, I did not understand you did scf-calculations<BR>> using 2x2x2 k-mesh, and then made phonon calculations.<BR>> If so, nr1=2 and etc. is not correct. <BR>> Here you have to specify q-points mesh different of<BR>> k-points used in scf-calculations. Then q2r will be<BR>> able to do FFT F(q)=>F(R). So, you should put here <BR>> nr1=1 etc. as you used only the Gamma point. Is the<BR>> use only the Gamma point is OK for FFT, some doubts. <BR>> <BR>> Probably, you have an enormous computational resource<BR>> and are very ambitious to calculate phonons for 64<BR>> atoms supercell. For ideal case these properties you<BR>> would like to calculate is just 32 times that these<BR>> for 2 atomic cell. <BR>
<BR>;( No, I haven't enormous eomputational resource and I'm just a little novice on phonons calculation. I find the resource the phonon calculation needed is out of my expection when I first touch it. For the aim of obtaining some properties of point-defects in Si-supercell, I try to make the perfect Si-bulk as reference. And for consistency I use the same k-points, supercell and cutoffs as initial geometry optimization. The phonons calculation is so expensive that I have to just calculate the dynamical matrix at the gamma point of the supercell.<BR>
<BR>> Bests,<BR>> Eyvaz.<BR>> <BR><BR>
yours, shangyi<BR>
Best regards!<BR>
<BR>Graduate school of China academy of science <BR><BR><br /><hr />探索 Windows Vista 的世界 <a href='http://search.live.com/results.aspx?q=windows+vista&mkt=zh-cn&FORM=LIVSOP' target='_new'>了解更多信息！</a></body>
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