<br clear="all">Hi,<div><br></div><div>I define the graphene ribbon(1-D), periodic in z direction by</div><div><br></div><div><div><br></div><div> </div><div> /</div><div> &system</div><div> </div><div> ibrav = 0</div>
<div><br></div><div>nat=60</div><div>ntyp=2</div><div>ecutwfc=50.0</div><div>ecutrho = 600.0</div><div>,</div><div> /</div><div> &electrons</div><div> conv_thr = 1.0d-6,</div><div> mixing_beta=0.05,</div><div> /</div>
<div><br></div><div>ATOMIC_SPECIES</div><div>C 12.0000 C.pz-rrkjus.UPF</div><div>H 1.00000 H.pz-rrkjus.UPF</div><div><br></div><div>ATOMIC_POSITIONS {angstrom}</div><div> C 5.000000e+00 6.005391e+00 2.864597e+00</div>
<div> C 5.000000e+00 7.195584e+00 3.619975e+00</div><div> C 5.000000e+00 6.005370e+00 1.482985e+00</div><div> C 5.000000e+00 8.420899e+00 2.896093e+00</div><div> C 5.000000e+00 9.650820e+00 3.625321e+00</div>
<div> C 5.000000e+00 7.195533e+00 7.276090e-01</div><div> C 5.000000e+00 8.420864e+00 1.451361e+00</div><div> C 5.000000e+00 1.086968e+01 2.895976e+00</div><div> C 5.000000e+00 1.209962e+01 3.625208e+00</div>
<div> C 5.000000e+00 9.650806e+00 7.222413e-01</div><div> C 5.000000e+00 1.086970e+01 1.451465e+00</div><div> C 5.000000e+00 1.332495e+01 2.901401e+00</div><div> C 5.000000e+00 1.451503e+01 3.657009e+00</div>
<div> C 5.000000e+00 1.209965e+01 7.223490e-01</div><div> C 5.000000e+00 1.332498e+01 1.446149e+00</div><div> C 5.000000e+00 1.451517e+01 6.907900e-01</div><div> H 5.000000e+00 5.029452e+00 3.377799e+00</div>
<div> H 5.000000e+00 5.029415e+00 9.698360e-01</div><div> H 5.000000e+00 1.549104e+01 3.143928e+00</div><div> H 5.000000e+00 1.549109e+01 1.204033e+00</div><div> C 5.000000e+00 6.005518e+00 7.212533e+00</div>
<div> C 5.000000e+00 7.195603e+00 7.968203e+00</div><div> C 5.000000e+00 6.005518e+00 5.830967e+00</div><div> C 5.000000e+00 8.420899e+00 7.244204e+00</div><div> C 5.000000e+00 9.650813e+00 7.973587e+00</div>
<div> C 5.000000e+00 7.195603e+00 5.075297e+00</div><div> C 5.000000e+00 8.420899e+00 5.799296e+00</div><div> C 5.000000e+00 1.086964e+01 7.244085e+00</div><div> C 5.000000e+00 1.209955e+01 7.973476e+00</div>
<div> C 5.000000e+00 9.650813e+00 5.069913e+00</div><div> C 5.000000e+00 1.086964e+01 5.799415e+00</div><div> C 5.000000e+00 1.332483e+01 7.249443e+00</div><div> C 5.000000e+00 1.451500e+01 8.004905e+00</div>
<div> C 5.000000e+00 1.209955e+01 5.070024e+00</div><div> C 5.000000e+00 1.332483e+01 5.794057e+00</div><div> C 5.000000e+00 1.451500e+01 5.038595e+00</div><div> H 5.000000e+00 5.029453e+00 7.725544e+00</div>
<div> H 5.000000e+00 5.029453e+00 5.317956e+00</div><div> H 5.000000e+00 1.549104e+01 7.491852e+00</div><div> H 5.000000e+00 1.549104e+01 5.551648e+00</div><div> C 5.000000e+00 6.005370e+00 1.156051e+01</div>
<div> C 5.000000e+00 7.195533e+00 1.231589e+01</div><div> C 5.000000e+00 6.005391e+00 1.017890e+01</div><div> C 5.000000e+00 8.420864e+00 1.159214e+01</div><div> C 5.000000e+00 9.650806e+00 1.232126e+01</div>
<div> C 5.000000e+00 7.195584e+00 9.423525e+00</div><div> C 5.000000e+00 8.420899e+00 1.014741e+01</div><div> C 5.000000e+00 1.086970e+01 1.159203e+01</div><div> C 5.000000e+00 1.209965e+01 1.232115e+01</div>
<div> C 5.000000e+00 9.650820e+00 9.418179e+00</div><div> C 5.000000e+00 1.086968e+01 1.014752e+01</div><div> C 5.000000e+00 1.332498e+01 1.159735e+01</div><div> C 5.000000e+00 1.451517e+01 1.235271e+01</div>
<div> C 5.000000e+00 1.209962e+01 9.418292e+00</div><div> C 5.000000e+00 1.332495e+01 1.014210e+01</div><div> C 5.000000e+00 1.451503e+01 9.386491e+00</div><div> H 5.000000e+00 5.029415e+00 1.207366e+01</div>
<div> H 5.000000e+00 5.029452e+00 9.665701e+00</div><div> H 5.000000e+00 1.549109e+01 1.183947e+01</div><div> H 5.000000e+00 1.549104e+01 9.899572e+00</div><div><br></div><div><br></div><div>CELL_PARAMETERS</div>
<div>20.000000 0.000000 0.0000000 </div><div>0.0000000 45.96300 0.0000000</div><div>0.0000000 0.000000 24.648513</div><div><br></div><div>K_POINTS {automatic} </div><div>1 1 24 0 0 0</div></div><div><br></div><div><br></div>
<div>, the output file gives the following data</div><div><div>Parallel version (MPI), running on 24 processors</div><div> R & G space division: proc/pool = 24</div><div><br></div><div> Current dimensions of program PWSCF are:</div>
<div> Max number of different atomic species (ntypx) = 10</div><div> Max number of k-points (npk) = 40000</div><div> Max angular momentum in pseudopotentials (lmaxx) = 3</div><div> Waiting for input...</div>
<div> file C.pz-rrkjus.UPF: wavefunction(s) 2S renormalized</div><div> file H.pz-rrkjus.UPF: wavefunction(s) 1S renormalized</div><div><br></div><div> Subspace diagonalization in iterative solution of the eigenvalue problem:</div>
<div> parallel, distributed-memory algorithm (size of sub-group: 3* 3 procs)</div><div><br></div><div> warning: symmetry operation # 3 not allowed. fractional translation:</div><div> 0.0551369 0.0000000 -0.0000050 in crystal coordinates</div>
<div> warning: symmetry operation # 8 not allowed. fractional translation:</div><div> 0.0551369 0.0000000 0.0000000 in crystal coordinates</div><div><br></div><div> Stick Mesh</div><div> ----------</div>
<div> nst = 43869, nstw = 3781, nsts = 14625</div><div> <a href="http://n.st">n.st</a> n.stw n.sts n.g <a href="http://n.gw">n.gw</a> <a href="http://n.gs">n.gs</a></div><div> min 1827 157 609 234299 5945 45073</div>
<div> max 1828 159 610 234302 5948 45104</div><div> 43869 3781 14625 5623217 142709 1082119</div><div><br></div><div><br></div><div><br></div><div> bravais-lattice index = 0</div>
<div> lattice parameter (a_0) = 20.0000 a.u.</div><div> unit-cell volume = 22658.3921 (a.u.)^3</div><div> number of atoms/cell = 60</div><div> number of atomic types = 2</div>
<div> number of electrons = 204.00</div><div> number of Kohn-Sham states= 102</div><div> kinetic-energy cutoff = 50.0000 Ry</div><div> charge density cutoff = 600.0000 Ry</div>
<div> convergence threshold = 1.0E-06</div><div> mixing beta = 0.0500</div><div> number of iterations used = 8 plain mixing</div><div> Exchange-correlation = SLA PZ NOGX NOGC (1100)</div>
<div> EXX-fraction = 0.00</div><div><br></div><div> celldm(1)= 20.000000 celldm(2)= 0.000000 celldm(3)= 0.000000</div><div> celldm(4)= 0.000000 celldm(5)= 0.000000 celldm(6)= 0.000000</div>
<div><br></div><div> crystal axes: (cart. coord. in units of a_0)</div><div> a(1) = ( 1.000000 0.000000 0.000000 ) </div><div> a(2) = ( 0.000000 2.298150 0.000000 ) </div><div>
a(3) = ( 0.000000 0.000000 1.232426 ) </div><div><br></div><div> reciprocal axes: (cart. coord. in units 2 pi/a_0)</div><div> b(1) = ( 1.000000 0.000000 0.000000 ) </div><div> b(2) = ( 0.000000 0.435133 0.000000 ) </div>
<div> b(3) = ( 0.000000 0.000000 0.811408 ) </div><div><br></div></div><div><br></div><div>Am I making any mistake anywhere (considering a0=20,and celldm(3)=0 ), does it define 1-D , z periodic structure) ? , my box is orthorhombic, so should I specifically use ibrav and celldm instead of defining the cell parameters ?</div>
<div><br></div><div><br></div><div><br>-- <br>Regards,<br>Swapnil Chandratre<br>Graduate Student<br>Dept. of Mechanical Engineering,<br>University of Houston,<br>Houston, TX<br>(M)-713-294-9546<br>
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