<table cellspacing="0" cellpadding="0" border="0" ><tr><td valign="top" style="font: inherit;"><br> Gentlemen,<br><br>My structures do not see to be converging
with increased ecutwfc. I'm setting ecutrho to ecutwfc * 12 and using
US PP. below is a table of ecut values vs energies vs difference
from previous steps followed by my input file followed by part of the output
file. It appears to begin to converge and 120 ecut but then jumps at
130 and then more at 140. I understood that convergence should be
pretty well achieved by 30 ecut for US PP. The only thing I change
between runs are the two ecut parameters. Any ideas as to what I'm
doing wrong or what I should be expecting? <br><br>A follow up
question in that I'm trying to do vc-relax based on this scf and the
forces decrease until a value of about 0.0003 and then oscillate around
this value. could that be related to the ecut convergence problem
I'm having?<br><br>thanks,<br><br>Tim Mason, University of Missouri St. Louis Department of Physics and astronomy<br>------------------------------------------------------------------------------------<br>ecutwfc total energy difference from previous <br><br>100 -48.21607621<br>105 -48.21651331 0.0004371<br>110 -48.21672787 0.00021456<br>120 -48.21686396 0.00013609<br>130 -48.2172448 0.00038084<br>140 -48.21819748 0.00095268<br><br><br>----------------------------------------------------------------------<br>&CONTROL<br>calculation = "scf",<br>prefix = 'n4_scf.out',<br>tprnfor = .TRUE.<br>pseudo_dir =
'/home/thmmqc/pwscf/psps/US_GGA',<br>outdir='/home/thmmqc/tmp'<br>etot_conv_thr = 1.d-8<br>/<br><br>&SYSTEM<br>ibrav =
0, nat = 8, ntyp = 3,<br>ecutwfc = 100<br>ecutrho = 1200<br>celldm(1) = 1.889725989<br><br>/<br><br>&ELECTRONS<br>diagonalization = 'cg',<br>mixing_mode = 'plain',<br>mixing_beta = 0.7,<br>conv_thr = 1.0D-8<br>/<br><br><br>ATOMIC_SPECIES<br>Li 6.941000 Li.pbe-n-van.UPF<br>N 14.006740 N.pbe-van_ak.UPF<br>H 1.007940 H.pbe-van_ak.UPF<br><br>CELL_PARAMETERS<br>10.52658029 -1.08441956 -0.28831668 <br>-2.96581684 6.61198966 -0.14661465 <br>1.15738394 0.29429438 3.51384172 <br><br>ATOMIC_POSITIONS {crystal}<br>Li 0.<span style="border-bottom: 1px dashed rgb(0, 102, 204); cursor: pointer;" class="yshortcuts" id="lw_1225985948_0">403906747000</span> 0.720101910000 0.<span style="border-bottom: 1px dashed rgb(0, 102, 204); cursor: pointer;" class="yshortcuts" id="lw_1225985948_1">473406799000</span> <br>Li 0.228004145000 0.310445951000 0.053578743000 <br> N 0.230067712000 0.<span style="border-bottom: 1px dashed rgb(0, 102, 204); cursor: pointer;"
class="yshortcuts" id="lw_1225985948_2">303154666000</span> 0.552891390000 <br> N 0.403264134000 0.730145360000 -0.024840278000 <br> H 0.185705821000 0.137557379000 0.553855070000 <br> H 0.132830606000 0.<span style="border-bottom: 1px dashed rgb(0, 102, 204); cursor: pointer;" class="yshortcuts" id="lw_1225985948_3">318409519000</span> 0.624406047000 <br> H 0.486061391000 0.<span style="border-bottom: 1px dashed rgb(0, 102, 204); cursor: pointer;" class="yshortcuts" id="lw_1225985948_4">685122024000</span> -0.095482152000 <br> H 0.<span style="border-bottom: 1px dashed rgb(0, 102, 204); cursor: pointer;" class="yshortcuts" id="lw_1225985948_5">467101514000</span> 0.<span style="border-bottom: 1px dashed rgb(0, 102, 204); cursor: pointer;" class="yshortcuts" id="lw_1225985948_6">897467040000</span> -0.<span style="border-bottom: 1px dashed rgb(0, 102, 204); cursor: pointer;" class="yshortcuts"
id="lw_1225985948_7">051109646000</span>
<br><br>K_POINTS automatic<br>2 2 2 0 0 0 <br><br>---------------------------------------------------------------------------------------------------------------------<br><br> Program PWSCF v.4.0.2 starts ...<br> Today is 6Nov2008 at 8:30: 1 <br><br> Parallel version (MPI)<br><br> Number of processors in use: 1<br><br> For Norm-Conserving or Ultrasoft (Vanderbilt) Pseudopotentials or PAW<br><br> Current dimensions of program pwscf are:<br> Max number of different atomic species (ntypx) = 10<br> Max number of k-points (npk) = 40000<br> Max <span class="yshortcuts" id="lw_1225985948_8">angular momentum</span> in pseudopotentials (lmaxx) =
3<br><br> Iterative solution of the
eigenvalue problem<br> Too few procs for parallel algorithm<br> we need at least 4 procs per pool<br><br> a serial algorithm will be used<br><br><br> Planes per process (thick) : nr3 = 96 npp = 96 ncplane =51840<br> Planes per process (smooth): nr3s= 54 npps= 54 ncplanes=17280<br> <br> Proc/ planes cols G planes cols G columns G<br> Pool (dense grid) (smooth grid) (wavefct grid)<br> 1 96 32843 1954809 54 10579 357021 2893
51177<br> <br><br><br> bravais-lattice index = 0<br> lattice parameter (a_0) = 1.8897 a.u.<br> unit-cell volume = 1595.0644 (a.u.)^3<br> number of atoms/cell = 8<br> number of atomic types = 3<br> <span style="border-bottom: 1px dashed rgb(0, 102, 204); cursor: pointer;" class="yshortcuts" id="lw_1225985948_9">number of electrons</span> =
16.00<br> number of Kohn-Sham
states= 8<br> kinetic-energy cutoff = 140.0000 <span style="border-bottom: 1px dashed rgb(0, 102, 204); cursor: pointer;" class="yshortcuts" id="lw_1225985948_10">Ry</span><br> <span class="yshortcuts" id="lw_1225985948_11">charge density</span> cutoff = 1740.0000 Ry<br> convergence threshold = 1.0E-08<br> mixing beta = 0.7000<br> number of iterations used = 8 plain mixing<br>
Exchange-correlation = SLA PW PBE PBE (1434)<br><br> celldm(1)= 1.889726
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) = ( 10.526580 -1.084420 -0.288317 ) <br> a(2) = ( -2.965817 6.611990 -0.146615 ) <br> a(3) = ( 1.157384 0.294294 3.513842 ) <br><br> reciprocal axes: (cart. coord. in units 2 pi/a_0)<br> b(1) = ( 0.098478 0.043373 -0.036069 )
<br> b(2) = ( 0.015762 0.157902 -0.018417 ) <br> b(3) = ( 0.008738 0.010147 0.280861 ) <br><br><br> PseudoPot. # 1 for Li read from file Li.pbe-n-van.UPF<br> Pseudo is Ultrasoft + core correction, Zval = 1.0<br> Generated by new atomic code, or converted to UPF format<br> Using radial grid of 751 points, 2 beta functions with: <br> l(1) = 1<br> l(2) = 1<br> Q(r) pseudized with 8 coefficients, rinner
= 1.000 1.000 1.000<br><br><br> PseudoPot. # 2 for N read from file N.pbe-van_ak.UPF<br> Pseudo is Ultrasoft, Zval = 5.0<br> Generated by new atomic code, or converted to UPF format<br> Using radial grid of 729 points, 4 beta functions with: <br> l(1) = 0<br> l(2) = 0<br> l(3) = 1<br> l(4) = 1<br> Q(r) pseudized with 8 coefficients, rinner =
0.800 0.800 0.800<br><br><br> PseudoPot. # 3 for H read from file H.pbe-van_ak.UPF<br> Pseudo is Ultrasoft, Zval = 1.0<br> Generated by new atomic code, or converted to UPF format<br> Using radial grid of 615 points, 1 beta functions with: <br> l(1) = 0<br> Q(r) pseudized with 8 coefficients, rinner = 0.800<br><br> atomic species valence mass pseudopotential<br> Li 1.00 6.94100 Li(
1.00)<br> N 5.00 14.00674 N ( 1.00)<br> H 1.00 1.00794 H ( 1.00)<br><br> No symmetry!<br><br> Cartesian axes<br><br> site n. atom positions (a_0 units)<br> 1 Li tau( 1) = ( 2.6639799 4.4626230 1.4414460 )<br>
2 Li tau( 2) = ( 1.5413893 1.8211812 0.0770139 )<br> 3 N tau( 3) = ( 2.1626326 1.9176784 1.8319936 )<br> 4 N tau( 4) = ( 2.0507651 4.3830957 -0.3106026 )<br> 5 H tau( 5) = ( 2.1879002 0.8711414 1.8724490 )<br> 6 H tau( 6) =
( 1.1765853 2.1450355 2.1090832 )<br> 7 H tau( 7) = ( 2.9741083 3.9748254 -0.5760977 )<br> 8 H tau( 8) = ( 2.1961052 5.4124675 -0.4458462 )<br><br> <br> Self-consistent Calculation<br><br> iteration # 1 ecut= 140.00 Ry beta=0.70<br> CG style diagonalization<br> ethr = 1.00E-02, avg #
of iterations = 3.3<br><br> negative rho (up, down): 0.143E-04 0.000E+00<br><br> <br></td></tr></table>