<html><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:14pt"><div id="yiv1670408046"><div><div style="color:#000;background-color:#fff;font-family:times new roman, new york, times, serif;font-size:14pt;"><div>Dear <span class="yiv1670408046tab">Q.E Users.</span></div><div style="color:rgb(0, 0, 0);font-size:18.6667px;font-family:times new roman, new york, times, serif;background-color:transparent;font-style:normal;"><span class="yiv1670408046tab">I
 have a system of 4x4 graphene supercell, comprising 32 carbon 
atoms. I sucessfully run all the calculations i.e scf,nscf and other 
postprocessing such as DOS and PDOS. But the main problem i'm facing 
currently is on the density of state. Usually, i consider zero to be my 
fermi reference energy point in my ./dos.x input file, forexample,from 
-10 and 10 as my Emin and Emax respectivily. For pristine graphene,i 
expect to always see the dispersion at the </span><span class="yiv1670408046tab">zero </span><span class="yiv1670408046tab">vicinity,

 showing a semi metallic behavior, but surprisingly, its always moving 
away from zero to
 around -2, in the valence band side which i knew is unsual for pristine
 
graphene. However, when i combine graphene with GaAs nanostructure, most
 of the interesting properties interms of orbitals contributions (PDOS),
 also resides on similar point -2. That is some of the contributions 
that are supposed to be seen at the vicinity of the fermi level, now 
moved to another point -2. Also, i consider changing the smearing from 
marzari-vanderbilt to Fermi- Dirac, but similar 
properties were observed. I decided to consider only 1x1, and 2x2 
graphene supercell alone, still similar properties i observed also. In 
fact, i even consider changing my pseudopotential from pw91 to 
pbe.rrkjus still no progress. My 
problem now, i don't know what really causes these shift from 0 to -2. <br></span></div><div style="color:rgb(0, 0, 0);font-size:18.6667px;font-family:times new roman, new york, times, serif;background-color:transparent;font-style:normal;"><span class="yiv1670408046tab">I attached one of my graphene scf input file for your verification and
 advice.</span></div><div style="color:rgb(0, 0, 0);font-size:18.6667px;font-family:times new roman, new york, times, serif;background-color:transparent;font-style:normal;"><br><span class="yiv1670408046tab"></span></div><div style="color:rgb(0, 0, 0);font-size:18.6667px;font-family:times new roman, new york, times, serif;background-color:transparent;font-style:normal;"><span class="yiv1670408046tab"> &CONTROL<br>                    title = 'Graphene monolayer01',<br>                      prefix = 'Graph01',<br>                 calculation = 'scf' ,<br>                restart_mode = 'from_scratch'
 ,<br>                     outdir = '/home/</span><span class="yiv1670408046tab">/???</span><span class="yiv1670408046tab">/espresso-4.1.2/bin/' ,<br>                  pseudo_dir = '/home/</span><span class="yiv1670408046tab">/???</span><span class="yiv1670408046tab">/???/espresso-4.1.2/upf_files/' ,<br>               <br>                     tstress = .true. ,<br>                     tprnfor = .true.
 ,<br> /<br> &SYSTEM<br>                       ibrav = 4,<br>                   celldm(1) = 18.59490373,<br>                   celldm(3) = 1.80,<br>                         nat = 32,<br>                        ntyp = 1,<br>                     ecutwfc = 34.D0
 ,<br>                  tot_charge = 0.000000,<br>                 occupations = 'smearing' ,<br>                     degauss = 0.02 ,<br>                    smearing = 'fermi-dirac' ,<br>                     <br> /<br> &ELECTRONS<br>                    conv_thr = 1.D-8 ,<br>                 mixing_beta = 0.7D0
 ,<br> /<br>ATOMIC_SPECIES<br>     C   12.00000  C.pw91-van_ak.UPF <br>    <br>ATOMIC_POSITIONS (angstrom)<br>C        1.229999657   0.709326753   1.999999753<br>C        2.459999165   1.419486000   1.999999874<br>C        3.689999208   0.709327391   1.999999822<br>C        4.920000000   1.419486496   1.999999944<br>C        4.920000000   2.839880146   2.000000125<br>C        6.149999990   3.549976521   1.999999907<br>C        3.690000010   3.549976521   1.999999907<br>C       
 2.459999764   2.839879152   2.000000067<br>C        6.150000792   0.709327391   1.999999822<br>C        7.380000835   1.419486000   1.999999874<br>C        7.380000236   2.839879152   2.000000067<br>C        8.610000005   3.549975943   1.999999891<br>C        8.609999654   4.970023341   2.000000208<br>C        9.840000000   5.680120078   2.000000200<br>C        7.379999382   5.680120770   2.000000152<br>C        6.149999800   4.970024086   2.000000150<br>C       
 4.920000000   5.680121474   2.000000132<br>C        3.690000200   4.970024086   2.000000150<br>C        8.610000343   0.709326753   1.999999753<br>C        9.840000000   1.419485253   1.999999874<br>C        9.840000000   2.839878353   2.000000070<br>C       11.069999995   3.549975943   1.999999891<br>C       11.070000346   4.970023341   2.000000208<br>C       12.300000618   5.680120770   2.000000152<br>C       12.300001137   7.100514050   2.000000166<br>C       13.530000464  
 7.810673002   1.999999744<br>C       11.070000830   7.810672948   1.999999928<br>C        9.840000000   7.100514025   2.000000287<br>C        8.609999170   7.810672948   1.999999928<br>C        7.379998863   7.100514050   2.000000166<br>C        6.149999536   7.810673002   1.999999744<br>C        4.920000000   7.100514261   2.000000041<br>      <br>K_POINTS automatic <br>  6 6 1   0 0 0 </span></div><div style="color:rgb(0, 0, 0);font-size:18.6667px;font-family:times new roman, new york, times, serif;background-color:transparent;font-style:normal;"><br><span
 class="yiv1670408046tab"></span></div><div style="color:rgb(0, 0, 0);font-size:18.6667px;font-family:times new roman, new york, times, serif;background-color:transparent;font-style:normal;"><span class="yiv1670408046tab">Thank you for your kind response.</span></div><div style="color:rgb(0, 0, 0);font-size:18.6667px;font-family:times new roman, new york, times, serif;background-color:transparent;font-style:normal;"><br><span class="yiv1670408046tab"></span></div><div style="color:rgb(0, 0, 0);font-size:18.6667px;font-family:times new roman, new york, times, serif;background-color:transparent;font-style:normal;"><span class="yiv1670408046tab">Shamsu Abubakar</span></div><div style="color:rgb(0, 0, 0);font-size:18.6667px;font-family:times new roman, new york, times, serif;background-color:transparent;font-style:normal;"><span class="yiv1670408046tab">Postgraduate student<br></span></div><div style="color:rgb(0, 0, 0);font-size:18.6667px;font-family:times
 new roman, new york, times, serif;background-color:transparent;font-style:normal;"><span class="yiv1670408046tab">Department of Physics</span></div><span class="yiv1670408046tab">University Putra Malaysia</span></div></div></div>         <div id="slot_RS"><div id="RS"> </div></div><div id="slot_RS2"><div id="RS2"> </div></div>



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