Menu

Documentation

Elk Users
julian
2016-04-09
2016-04-16
  • julian

    julian - 2016-04-09

    Hi everyone,

    I don't know if it is a mistake in the documentation, since online and shipped with the source code only the documentation for elk-3-3.15 is available, but at least there the default for lmaxmat = 6 is not the one that is used in elk-3-3.17, which is lmaxmat = 7.

    This issue rises two questions:
    1) Is there somewhere a corrected version of the documentation for 3-3-17?
    2) Is there any way of determining the input parameters not set in elk.in? It doesn't seem like such a list is printed in any of the output files (if not I think this is a helpful feature)

     
  • mfechner

    mfechner - 2016-04-09

    Dear Full Name ?,

    your comment is correct concerning the changed lmaxmat value, however, elk is a very good documented code if you go through the manual especially regarding other commercial available pseudopotential codes which are widely used.

    Anyway for me the best way to check the defaul flags is by looking into

    readinput.f90 which contains all defaults variables of the code.

    best regards
    Michael

     
  • julian

    julian - 2016-04-09

    Dear Michael,

    thank you for your comment. The intention of my comment whas not to critizise the documentation or the developers, rather to ask for a more up to date documentation in case I have overlooked it. Usually, I contact the manual first instead of the code itself as a new user. (Besides I always think printing the actual Input values at startup is usually a nice feature to have, since things can go wrong (typo, unexcpected syntax issue) but this is only a suggestion)

    Regards,

    Julian

     
  • julian

    julian - 2016-04-15

    epsstress=1.d-3 vs. the 5.d-4 in the manual

    I guess I should just stop looking into the manual...

    Concerning this parameter I would have a question: The way it is implemented I think less symmetric cases are unreasonably punished, since every contribution has to be much better converged due to the summation, or is there any weighting in the case of highly symmetric cases I have overlooked? In other words, I think the more components there are, the larger one can/should choose epsstress?

    I am asking because I have a case were the optimizer keeps oscillating around the correct volume. I increased the energy criterion to get more reliable energies (for better forces or in this case stress) and after a while the step size. Nevertheless, the lattice optimization won't converge (or eventually by luck). Is their a reliable way to tune the lattice optimization or is it, at present, just better to compute single-points vaying the lattice manually because the optimizer is not robust enough?

    Attatched find step, volume, and energy of the optimization:
    1 78.95624702 -1272.81045476
    2 78.76195705 -1272.81045562
    3 78.41810890 -1272.81049903
    4 77.75995338 -1272.81067923
    5 76.25456230 -1272.81105735
    6 74.43341670 -1272.81136621
    7 73.67268518 -1272.81115429
    8 73.73955675 -1272.81094813
    9 74.04579388 -1272.81099870
    10 74.57551949 -1272.81114554
    11 75.20424270 -1272.81130712
    12 75.75801729 -1272.81138582
    13 76.14654521 -1272.81138632
    14 76.32867240 -1272.81138582
    15 76.40775138 -1272.81139120
    16 76.38586069 -1272.81140596
    17 76.26725668 -1272.81143010
    18 76.06088707 -1272.81146727
    19 75.79056199 -1272.81151064
    20 75.42486712 -1272.81154412
    21 75.76091593 -1272.81154414
    22 75.64239815 -1272.81154365
    23 75.51171510 -1272.81154076
    24 75.47261064 -1272.81153602
    25 75.46772440 -1272.81154163
    26 75.49190729 -1272.81155143
    27 75.52218936 -1272.81155799
    28 75.45922763 -1272.81156099
    29 75.31667471 -1272.81155966
    30 75.17563529 -1272.81155170
    31 75.17833399 -1272.81154728
    32 75.23436588 -1272.81154694
    33 75.31396566 -1272.81155306
    34 75.39857472 -1272.81154800
    35 75.50186271 -1272.81155428
    36 75.57446842 -1272.81155843
    37 75.57017389 -1272.81155999
    38 75.49233908 -1272.81156012
    39 75.38649942 -1272.81155879
    40 75.32688705 -1272.81155498
    41 75.38964147 -1272.81155499
    42 75.40500690 -1272.81155521
    43 75.43241077 -1272.81155612
    44 75.46306816 -1272.81155802
    45 75.48911801 -1272.81155957
    46 75.47076663 -1272.81156074
    47 75.41230385 -1272.81155972
    48 75.35721745 -1272.81155718
    49 75.36386595 -1272.81155419
    50 75.41909558 -1272.81155470
    51 75.47325412 -1272.81155731
    52 75.47203069 -1272.81155829
    53 75.37669355 -1272.81155904
    54 75.25365431 -1272.81155620
    55 75.22745829 -1272.81154708
    56 75.21380949 -1272.81155804
    57 75.15228884 -1272.81155674
    58 75.13265701 -1272.81155080
    59 75.15037516 -1272.81154625
    60 75.19578132 -1272.81154780
    61 75.15599526 -1272.81154780
    62 75.18285790 -1272.81154910
    63 75.24582276 -1272.81155422
    64 75.27407603 -1272.81156144
    65 75.28340242 -1272.81155059
    66 75.29223570 -1272.81155007
    67 75.28145318 -1272.81155112
    68 75.23556220 -1272.81155040
    69 75.17613213 -1272.81156011
    70 75.07921376 -1272.81155401
    71 75.05134717 -1272.81154475
    72 75.08663883 -1272.81154282
    73 75.17718234 -1272.81154703
    74 75.24568559 -1272.81155583
    75 75.28115132 -1272.81155015
    76 75.34886682 -1272.81155185
    77 75.39096272 -1272.81155478
    78 75.39358367 -1272.81155711
    79 75.37111610 -1272.81155783
    80 75.36782123 -1272.81155625
    81 75.37144150 -1272.81155626
    82 75.37302254 -1272.81155633
    83 75.37602023 -1272.81155642
    84 75.38142757 -1272.81155561
    85 75.39010776 -1272.81155615
    86 75.40170116 -1272.81155621
    87 75.41414417 -1272.81155778
    88 75.42531080 -1272.81155849
    89 75.43569399 -1272.81155896
    90 75.43290616 -1272.81155827
    91 75.41592394 -1272.81155840
    92 75.38981214 -1272.81155817
    93 75.36572239 -1272.81155708
    94 75.35154453 -1272.81155602
    95 75.34921296 -1272.81155592
    96 75.35548637 -1272.81155561
    97 75.36567439 -1272.81155585
    98 75.38031426 -1272.81155608
    99 75.39875653 -1272.81155723
    100 75.40768542 -1272.81155803
    101 75.39660505 -1272.81155804
    102 75.38575693 -1272.81155802
    103 75.37272392 -1272.81155768
    104 75.36897514 -1272.81155693
    105 75.37505490 -1272.81155658
    106 75.38436604 -1272.81155674
    107 75.39632182 -1272.81155727
    108 75.40925228 -1272.81155792
    109 75.42205109 -1272.81155830
    110 75.42741725 -1272.81155858
    111 75.42467327 -1272.81155853
    112 75.41956608 -1272.81155843
    113 75.42201936 -1272.81155817
    114 75.42456765 -1272.81155765
    115 75.42728674 -1272.81155819
    116 75.43346353 -1272.81155830
    117 75.43662221 -1272.81155847
    118 75.43045006 -1272.81155878
    119 75.41319827 -1272.81155824
    120 75.39408418 -1272.81155749
    121 75.41249635 -1272.81155759
    122 75.40903522 -1272.81155754
    123 75.40633014 -1272.81155774
    124 75.40893321 -1272.81155779
    125 75.41472073 -1272.81155843
    126 75.42297239 -1272.81155856
    127 75.42366863 -1272.81155880
    128 75.41524276 -1272.81155874
    129 75.40355406 -1272.81155860
    130 75.40016129 -1272.81155767
    131 75.40560560 -1272.81155742
    132 75.41422416 -1272.81155782
    133 75.42601378 -1272.81155832
    134 75.44000218 -1272.81155862
    135 75.44801935 -1272.81155872
    136 75.43771973 -1272.81155998
    137 75.40973692 -1272.81155868
    138 75.38252818 -1272.81155756
    139 75.37459024 -1272.81155686
    140 75.38139424 -1272.81155656
    141 75.37517510 -1272.81155656
    142 75.37806665 -1272.81155659
    143 75.38361302 -1272.81155674
    144 75.39161690 -1272.81155691
    145 75.40252686 -1272.81155724
    146 75.41745828 -1272.81155745
    147 75.43546269 -1272.81155843
    148 75.44193185 -1272.81155890
    149 75.43144673 -1272.81155987
    150 75.41183695 -1272.81155858
    151 75.39977944 -1272.81155770
    152 75.39963140 -1272.81155741
    153 75.40506415 -1272.81155751
    154 75.41346387 -1272.81155785
    155 75.42451241 -1272.81155841
    156 75.42979187 -1272.81155871
    157 75.42644526 -1272.81155869
    158 75.42056720 -1272.81155866
    159 75.42299649 -1272.81155843
    160 75.42779063 -1272.81155795

    tasks
    2

    maxlatvstp
    20

    bfieldc
    0.0 0.0 0.5

    spinpol
    .true.

    latvopt
    1

    epsengy
    3.5e-8

    epspot
    1.e-7

    epsstress
    1.e-3

    !decreased this after a while from the default, didn't help
    tau0latv
    0.05

    stype
    1

    swidth
    0.005

    !Broyden mixing
    mixtype
    3

    !PBE
    xctype
    20

    nempty
    8

    lmaxmat
    10

    lmaxvr
    7

    lmaxapw
    10

    rgkmax
    10.0

    isgkmax
    -2

    gmaxvr
    16.5

    trimvg
    .true.

    !11 11 11
    ngridk
    4 4 4

    species
    26
    'Fe' 'iron'
    55.845
    1.90
    10
    1 0 1 2
    2 0 1 2
    2 1 1 2
    2 1 2 4
    3 0 1 2
    3 1 1 2
    3 1 2 4
    3 2 2 4
    3 2 3 2
    4 0 1 2

    avec
    4.6818627718132975 0.0 0.0
    -1.560621023337564 4.41410251767245 0.0
    -1.560621023337564 -2.207049599180853 3.822725873285856

    atoms
    1 : nspecies
    'Fe.in' : spfname
    1 : natoms; atpos, bfcmt below
    0.0 0.0 0.0 0.0 0.0 0.0

     

    Last edit: julian 2016-04-16
  • Sangeeta Sharma

    Sangeeta Sharma - 2016-04-16

    Dear Julian,

    Thanks for pointing various places in which manual is lacking. We will correct it in near future.

    I want to take this opportunity to point out a few things about the ELK project. Neither of the main developers of the code are paid in anyway to maintain or run the code/forum. Hence the idea behind the forum is that the users of the code can help each other when they encounter similar problems. By now many of the users are much better at running the code than Kay or myself and forum helps us use their expertise. We try to keep the environment in the forum friendly and recommend that people pose questions and help each other and us by pointing potential bugs. We highly recommend not using it as a "frustration outlet".

    As for the code, it is a constantly changing and developing code. The idea behind it is to be able to put in some of the latest ideas and cutting edge physics. This means manual is and probably will stay lagging behind. It is important to note that such an on going and fast developing projects are not for everyone. Some people prefer static codes with well laid out manual, which elk certainly is not. In such a situation one of the commercial package is much more suited.

    I hope soon one of the expert users will be able to help you resolve the issues.

    Best
    Sangeeta

     

Log in to post a comment.