<div>Dear Ding and D<font color="#5b1094">egiron</font></div>
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<div>i think about my problem again ,i think my lattice not belongs cubic neither triangular lattice .it is unuall lattice .a=b, the angle of a and b is 30 degree.a,b plumb <a href="http://c.it">c.it</a> is supercell. thank your hints. i have to redesign it .
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<div><span class="gmail_quote">2007/5/25, degironc <<a href="mailto:degironc@sissa.it">degironc@sissa.it</a>>:</span>
<blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">the word "cubic" is a reminder for the code that the symmetry group of<br>the crystal in a subset of the cubic one (the other option would be
<br>"hexagonal"). this does not means that the system is actually cubic but<br>just that the symmetry operations that it satisfies should be searched<br>among those of the cubic group.<br>.. is "cubic" the right symmetry system for your crystal ? the
<br>fundamental lattice vectors you get look like belonging to some<br>triangular lattice...<br>stefa<br><br>xu yuehua wrote:<br>> hi all :<br>> In the *.dynG file ,there is "cubic" ,i don know what is meaning
<br>> ,because my cell is not the type as you can see my scf file<br>><br>> -------------------------------------dynG.FILE<br>> ------------------------------<br>><br>> Dynamical matrix file<br>><br>> 2 15 0
38.1852405 0.0000000 0.0000000 0.0000000 0.0000000<br>> 0.0000000<br>> cubic<br>> 0.866025710 0.499999470 0.000000000<br>> 0.000000000 0.999998940 0.000000000<br>> 0.000000000
0.000000000 0.143563323<br>><br>> ------------------------------------------------------------------------scf<br>> file -----------------------------------<br>> this is the scf output :<br>><br>> bravais-lattice index = 0
<br>> lattice parameter (a_0) = 38.1852 a.u.<br>> unit-cell volume = 6922.4594 (a.u.)^3<br>> number of atoms/cell = 15<br>> number of atomic types = 2
<br>> kinetic-energy cutoff = 29.9874 Ry<br>> charge density cutoff = 200.0000 Ry<br>> convergence threshold = 1.0E-09<br>> beta = 0.2000
<br>> number of iterations used = 8 plain mixing<br>> Exchange-correlation = SLA PW PBE PBE (1434)<br>> celldm(1)= 38.185240 celldm(2)= 0.000000 celldm(3)= 0.000000
<br>> celldm(4)= 0.000000 celldm(5)= 0.000000 celldm(6)= 0.000000<br>><br>> crystal axes: (cart. coord. in units of a_0)<br>> a(1) = ( 0.866026 0.499999 0.000000 )<br>> a(2) = (
0.000000 0.999999 0.000000 )<br>> a(3) = ( 0.000000 0.000000 0.143563 )<br>><br>><br>><br>><br>><br>><br>><br>><br>><br>><br>><br>><br>> --<br>> Xu Yuehua<br>
> physics Department of Nanjing university<br>> China<br><br>_______________________________________________<br>Pw_forum mailing list<br><a href="mailto:Pw_forum@pwscf.org">Pw_forum@pwscf.org</a><br><a href="http://www.democritos.it/mailman/listinfo/pw_forum">
http://www.democritos.it/mailman/listinfo/pw_forum</a><br></blockquote></div><br><br clear="all"><br>-- <br>Xu Yuehua<br>physics Department of Nanjing university<br>China