<div class="gmail_quote">Dear All,<br><br>I am trying to optimize hydroxyapatite 1x1x2 and 1x1x1.<br>However, the atoms in the unit cell move into vacuum above the slab. See the figure below.<br><br>That is while optimization [scf] all the atoms move such that they occupy the vacuum above.<br>
I have worked with graphene but never faced such problems.<br><br>Can any one help me understanding why this might be happening.<br>Below is my input file.<br><br>----------------------------------------------------------------------------------------------------------------------------------------------<br>
&CONTROL<br> Calculation = "relax" ,<br> restart_mode = 'from_scratch' , <br> outdir ='/usr/espresso-4.3.2/',<br> pseudo_dir = '/usr/espresso-4.3.2/pseudo/',<br>
disk_io = 'default' ,<br> verbosity = 'default' ,<br> etot_conv_thr = 1.D-4 ,<br> forc_conv_thr = 1.D-3 ,<br> nstep = 500 ,<br>
dt = 40 ,<br>/<br>&SYSTEM<br> ibrav = 0,<br> nat = 96,<br> ntyp = 4,<br> ecutwfc = 10 ,<br> ecutrho = 80 ,<br>
occupations = 'smearing' ,<br> degauss = 0.02 ,<br>/<br>&ELECTRONS<br> electron_maxstep = 300,<br> Conv_thr = 1.0d-8 ,<br> mixing_mode = 'plain' ,<br>
mixing_beta = 0.5 ,<br> diagonalization = 'cg' ,<br> diago_cg_maxiter = 50,<br>/<br>&IONS<br>/<br>CELL_PARAMETERS<br> 17.80868385387 0.00000000000 0.00000000000<br>
-8.90434192693 15.42277262532 0.00000000000<br> 0.00000000000 0.00000000000 25.99871311373<br>ATOMIC_SPECIES<br> Ca 40.07800 Ca.pz-n-vbc.UPF<br> P 39.09830 P.pz-van_ak.UPF<br> O 15.99940 O.pz-van_ak.UPF <br>
H 1.007940 H.pz-van_ak.UPF<br>ATOMIC_POSITIONS angstrom<br>Ca -0.4710847875E-11 5.440920259 0.1031844561E-01<br>Ca -0.4710847875E-11 5.440920259 6.889282188 <br>Ca 4.711975164 2.720460129 13.74760904 <br>
Ca 4.711975164 2.720460129 6.868645296 <br>Ca 4.711975164 2.720460129 3.449800317 <br>Ca 4.711975164 2.720460129 10.32876406 <br>Ca 0.4713197894E-11 5.440920259 3.429163425 <br>
Ca 0.4713197894E-11 5.440920259 10.30812717 <br>Ca -2.355045187 8.107515277 1.719740935 <br>Ca -2.355045187 8.107515277 8.598704677 <br>Ca 7.067020351 0.5386511056E-01 12.03818655 <br>
Ca 7.067020351 0.5386511056E-01 5.159222806 <br>Ca 1.225113543 2.014228680 5.159222806 <br>Ca 1.225113543 2.014228680 12.03818655 <br>Ca 3.486861621 6.147151708 1.719740935 <br>
Ca 3.486861621 6.147151708 8.598704677 <br>Ca -1.131816434 2.068093790 1.719740935 <br>Ca -1.131816434 2.068093790 8.598704677 <br>Ca 5.843791598 6.093286598 12.03818655 <br>
Ca 5.843791598 6.093286598 5.159222806 <br>P 2.020966148 3.007468673 1.719740935 <br>P 2.020966148 3.007468673 8.598704677 <br>P 2.691009016 5.153911715 12.03818655 <br>
P 2.691009016 5.153911715 5.159222806 <br>P -1.594061198 3.253942361 5.159222806 <br>P -1.594061198 3.253942361 12.03818655 <br>P 6.306036362 4.907438027 1.719740935 <br>
P 6.306036362 4.907438027 8.598704677 <br>P 5.808922982 0.2464736877 1.719740935 <br>P 5.808922982 0.2464736877 8.598704677 <br>P -1.096947818 7.914906700 12.03818655 <br>
P -1.096947818 7.914906700 5.159222806 <br>O 0.8104597282 3.956637212 1.719740935 <br>O 0.8104597282 3.956637212 8.598704677 <br>O 3.901515436 4.204743176 12.03818655 <br>
O 3.901515436 4.204743176 5.159222806 <br>O 6.402631853 2.680197319 5.159222806 <br>O 6.402631853 2.680197319 12.03818655 <br>O -1.690656689 5.481183068 1.719740935 <br>
O -1.690656689 5.481183068 8.598704677 <br>O 0.8801969606 6.884940495 1.719740935 <br>O 0.8801969606 6.884940495 8.598704677 <br>O 3.831778203 1.276439893 12.03818655 <br>
O 3.831778203 1.276439893 5.159222806 <br>O 3.343146379 3.795858018 1.719740935 <br>O 3.343146379 3.795858018 8.598704677 <br>O 1.368828785 4.365522369 12.03818655 <br>
O 1.368828785 4.365522369 5.159222806 <br>O -1.615736284 4.793178702 5.159222806 <br>O -1.615736284 4.793178702 12.03818655 <br>O 6.327711448 3.368201686 1.719740935 <br>
O 6.327711448 3.368201686 8.598704677 <br>O 4.465067665 0.9973206834 1.719740935 <br>O 4.465067665 0.9973206834 8.598704677 <br>O 0.2469074986 7.164059704 12.03818655 <br>
O 0.2469074986 7.164059704 5.159222806 <br>O 2.023793333 2.104820002 0.4829032547 <br>O 2.023793333 2.104820002 7.361866997 <br>O 2.688181831 6.056560386 13.27502423 <br>
O 2.688181831 6.056560386 6.396060487 <br>O -0.8109309257 2.805066439 3.922385126 <br>O -0.8109309257 2.805066439 10.80134887 <br>O 5.522906090 5.356313949 2.956578616 <br>
O 5.522906090 5.356313949 9.835542358 <br>O 6.589226069 0.7002464373 0.4829032547 <br>O 6.589226069 0.7002464373 7.361866997 <br>O -1.877250905 7.461133951 13.27502423 <br>
O -1.877250905 7.461133951 6.396060487 <br>O 2.688181831 6.056560386 3.922385126 <br>O 2.688181831 6.056560386 10.80134887 <br>O 2.023793333 2.104820002 2.956578616 <br>
O 2.023793333 2.104820002 9.835542358 <br>O 5.522906090 5.356313949 0.4829032547 <br>O 5.522906090 5.356313949 7.361866997 <br>O -0.8109309257 2.805066439 13.27502423 <br>
O -0.8109309257 2.805066439 6.396060487 <br>O -1.877250905 7.461133951 3.922385126 <br>O -1.877250905 7.461133951 10.80134887 <br>O 6.589226069 0.7002464373 2.956578616 <br>
O 6.589226069 0.7002464373 9.835542358 <br>O 0.000000000 0.000000000 1.341397930 <br>O 0.000000000 0.000000000 8.220361672 <br>O 0.000000000 0.000000000 12.41652955 <br>
O 0.000000000 0.000000000 5.537565812 <br>O 0.000000000 0.000000000 4.780879801 <br>O 0.000000000 0.000000000 11.65984354 <br>O 0.000000000 0.000000000 2.098083941 <br>
O 0.000000000 0.000000000 8.977047683 <br>H 0.000000000 0.000000000 0.4182409955 <br>H 0.000000000 0.000000000 7.297204737 <br>H 0.000000000 0.000000000 13.33968649 <br>
H 0.000000000 0.000000000 6.460722746 <br>H 0.000000000 0.000000000 3.857722866 <br>H 0.000000000 0.000000000 10.73668661 <br>H 0.000000000 0.000000000 3.021240875 <br>
H 0.000000000 0.000000000 9.900204617<br>K_POINTS automatic<br> 1 1 1 0 0 0<br>----------------------------------------------------------------------------------------------------------------------------------------------<br>
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