[DFTB-Plus-User] Ionic relaxation

kousersummayya at jncasr.ac.in kousersummayya at jncasr.ac.in
Wed Apr 24 12:11:36 CEST 2013


Dear All,

I am exploring DFTB+ and see the compatibility with Quantum espresso (DFT).

I am working adsorption studies of H2S on monolayer of Zinc Oxide. I tried to relax the structure of monolayer of ZnO and obtained similar structures with DFTB+ and DFT (only relax).

But on putting a single molecule of H2S on 4x4 sheet of ZnO. The final structure is completely distorted when I relax with DFTB+ and the final structures from DFTB+ and Quantum espresso are completely different. Can you please let me know where I went wrong??

Here is the input file of dftb+

Geometry = {
TypeNames = { "Zn" "O" "H" "S" }
TypesAndCoordinates [Angstrom] = {
1    1.6262455740    0.9389126950    1.4947834250
2  -0.0117325830   -0.0067732800    1.4927709170
1   3.2596802350    3.7753831300    1.4971929010
2   1.6217020780    2.8296971550    1.4951803930
1   4.8931148960    6.6118535650    1.4996023770
2   3.2551367390    5.6661675900    1.4975898690
1   6.5265495570    9.4483240000    1.5020118530
2   4.8885714000    8.5026380250    1.4999993450
1   4.8994184460    0.9352740710    1.4971929330
2   3.2614402890   -0.0104119040    1.4951804250
1   6.5328531070    3.7717445060    1.4996024090
2   4.8948749500    2.8260585310    1.4975899010
1   8.1662877680    6.6082149410    1.5020118850
2   6.5283096110    5.6625289660    1.4999993770
1   9.7997224290    9.4446853760    1.5044213610
2   8.1617442720    8.4989994010    1.5024088530
1   8.1725913180    0.9316354470    1.4996024410
2   6.5346131610   -0.0140505280    1.4975899330
1   9.8060259790    3.7681058820    1.5020119170
2   8.1680478220    2.8224199070    1.4999994090
1  11.4394606400    6.6045763170    1.5044213930
2   9.8014824830    5.6588903420    1.5024088850
1  13.0728953010    9.4410467520    1.5068308690
2  11.4349171440    8.4953607770    1.5048183610
1  11.4457641900    0.9279968230    1.5020119490
2   9.8077860330   -0.0176891520    1.4999994410
1  13.0791988510    3.7644672580    1.5044214250
2  11.4412206940    2.8187812830    1.5024089170
1  14.7126335120    6.6009376930    1.5068309010
2  13.0746553550    5.6552517180    1.5048183930
1  16.3460681730    9.4374081280    1.5092403770
2  14.7080900160    8.4917221530    1.5072278690
4        8.200000000   5.200000000   2.989427051
3        7.229856377   5.200000000   3.933286475
3        9.170143623   5.200000000   3.933286475
}
Periodic = Yes
LatticeVectors [Angstrom] = {
13.092765712 -0.014554580 0.002409522
6.533775684 11.345946064 0.002409490
0.058609980 0.033839260 11.973212153
}
}
Driver = ConjugateGradient {
    MovedAtoms = 1:-1
    MaxForceComponent = 1e-4
    MaxSteps = 1500
    OutputPrefix = "geom.out"
    AppendGeometries = Yes
    LatticeOpt = No
    ConvergentForcesOnly = Yes 
}
Hamiltonian = DFTB {
    SCC = Yes
    SCCTolerance = 1e-8
    MaxSCCIterations = 600
    EwaldParameter = 0.0
    OrbitalResolvedSCC = No
    Mixer = Broyden{}
    SlaterKosterFiles = Type2FileNames {
    Prefix = "./"
    Separator = "-"
    Suffix = ".skf"
    LowerCaseTypeName = No
}
    MaxAngularMomentum {
        Zn  = "d"
        O = "p"
        H = "s"
        S = "p"
    }
    Filling = Fermi {
        Temperature [Kelvin] = 0.0
    }
    KPointsAndWeights = SuperCellFolding {
         7    0   0
         0    7   0
         0    0   1
        0.0 0.0 0.0
    }
    Dispersion = LennardJones {
    Parameters = UFFParameters {}
    }
}
Options {
    WriteEigenVectors = Yes
    WriteDetailedXML = Yes
    WriteResultsTag = Yes
    WriteDetailedOut = Yes
    AtomResolvedEnergies = Yes
    ShowFoldedCoords = Yes
}
ParserOptions {
    ParserVersion = 4
}



geom-out:

   35  S
 Zn  O  H  S
    1 1    0.1542969913E+01    0.7081213920E+00    0.1312795918E+01
    2 2    0.6470610621E+01    0.1112019224E+02    0.1782332176E+01
    3 1    0.3175597673E+01    0.3554161263E+01    0.1358394297E+01
    4 2    0.1534043958E+01    0.2605767992E+01    0.1077540004E+01
    5 1    0.4839480260E+01    0.6373389778E+01    0.1710563232E+01
    6 2    0.3219543413E+01    0.5464638153E+01    0.1221340248E+01
    7 1    0.6441991489E+01    0.9211498411E+01    0.1540384442E+01
    8 2    0.4812627442E+01    0.8280955528E+01    0.1931583356E+01
    9 1    0.4800893939E+01    0.7004579405E+00    0.1535877009E+01
   10 2    0.9731757123E+01    0.1109837379E+02    0.1067792497E+01
   11 1    0.6444632274E+01    0.3548714754E+01    0.1666707722E+01
   12 2    0.4776345489E+01    0.2594614008E+01    0.1780387714E+01
   13 1    0.8099867242E+01    0.6389647725E+01    0.1592021881E+01
   14 2    0.6475782651E+01    0.5428956956E+01    0.2026604309E+01
   15 1    0.9661964271E+01    0.9204202155E+01    0.1277107147E+01
   16 2    0.8016863354E+01    0.8257925833E+01    0.9863599514E+00
   17 1    0.8068678660E+01    0.6739682384E+00    0.1495326045E+01
   18 2    0.1296176861E+02    0.1107563664E+02    0.1822536348E+01
   19 1    0.9698336670E+01    0.3538371741E+01    0.1330020543E+01
   20 2    0.8044067896E+01    0.2571714051E+01    0.1269498252E+01
   21 1    0.1132749816E+02    0.6351087365E+01    0.1291369446E+01
   22 2    0.9684488491E+01    0.5426129884E+01    0.9932820219E+00
   23 1    0.1292762435E+02    0.9166871681E+01    0.1798712336E+01
   24 2    0.1123069863E+02    0.8209457850E+01    0.1920656598E+01
   25 1    0.1136306387E+02    0.6982746602E+00    0.1569109498E+01
   26 2    0.1626107673E+02    0.1107455414E+02    0.1304748477E+01
   27 1    0.1297785422E+02    0.3542871046E+01    0.1279464215E+01
   28 2    0.1134946222E+02    0.2615251128E+01    0.1678867318E+01
   29 1    0.1464390044E+02    0.6369807673E+01    0.1395090600E+01
   30 2    0.1299260233E+02    0.5453558378E+01    0.1064064615E+01
   31 1    0.1625031117E+02    0.9194992404E+01    0.1682269284E+01
   32 2    0.1459324373E+02    0.8232043567E+01    0.1834415344E+01
   33 4    0.9104155580E+01    0.7184715526E+01    0.4048575855E+01
   34 3    0.8372346831E+01    0.8318901475E+01    0.3953234011E+01
   35 3    0.1018832247E+02    0.7634116455E+01    0.3298785955E+01
    0.0000000000E+00    0.0000000000E+00    0.0000000000E+00
    0.1309276571E+02   -0.1455458000E-01    0.2409522000E-02
    0.6533775684E+01    0.1134594606E+02    0.2409490000E-02
    0.5860998000E-01    0.3383926000E-01    0.1197321215E+02

Please let me know if I am using wrong parameters.

-- 
Thanks,
Summayya Kouser,
Research Scholar,
JNCASR,
Bangalore.
Email: kouser.summayya at gmail.com.
Skype id: kouser.summayya


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