[DFTB-Plus-User] Band structure calculation for 2*2*2 Silicon supercell
Benjamin Hourahine
benjamin.hourahine at strath.ac.uk
Wed Sep 3 17:34:15 CEST 2014
Dear Susmita
the original behaviour is confusing, but harmless in this situation, so the MaxSCCIterations = 1 case should be used.
The warning is a consequence that the grid to generate the band structure does not correctly integrate the charge
contributions across the Brillouin zone, so should not be able to produce a converged self-consistent charge, but can
obtain a band structure for an already converged set of charges.
In the case of pure Si, self-consistency is not usually needed.
Regards
Ben
Dr. B. Hourahine, SUPA, Department of Physics,
University of Strathclyde, John Anderson Building,
107 Rottenrow, Glasgow G4 0NG, UK.
+44 141 548 2325, benjamin.hourahine at strath.ac.uk
2013/4 THE Awards Entrepreneurial University of the Year
2012/13 THE Awards UK University of the Year
The University of Strathclyde is a charitable body,
registered in Scotland, number SC015263
________________________________________
From: dftb-plus-user-bounces at mailman.zfn.uni-bremen.de [dftb-plus-user-bounces at mailman.zfn.uni-bremen.de] on behalf of Susmita Basak [basak at fhi-berlin.mpg.de]
Sent: 03 September 2014 16:15
To: dftb-plus-user at mailman.zfn.uni-bremen.de; Dftb plus user
Subject: [DFTB-Plus-User] Band structure calculation for 2*2*2 Silicon supercell
Dear DFTB+ Community Members,
I am trying to calculate band structure for a 2*2*2 Silicon supercell.
For band structure calculation if I use well converged charges from a
previous run I use the following tags in the input file:
SCC = Yes
ReadInitialCharges = Yes
MaxSCCIterations = 1
But this gave me the following error--
ERROR!
-> SCC is NOT converged, maximal SCC iterations exceeded
If I change the MaxSCCIterations value to 3 I obtain SCC convergence.
Is it okay to go ahead with the results of this run? Can anyone help me
with this ?
The input files I used are attached below.
Thanks and regards,
Susmita
Fritz Haber Institute of Max Planck Society, Berlin, Germany
=====================================================
#dftb_in.hsd
Geometry = GenFormat {
<<< "input_geometry.gen"
}
Hamiltonian = DFTB {
SCC = Yes
ReadInitialCharges = Yes
MaxSCCIterations = 3
SlaterKosterFiles = Type2FileNames {
Prefix =
"/mnt/lxfs1/home/basak/dftb/dftb+_1.2.2_autotest/slako/matsci-0-3/"
Separator = "-"
Suffix = ".skf"
}
MaxAngularMomentum {
Si = "d"
}
Filling = Fermi {
Temperature [Kelvin] = 0.0
}
KPointsAndWeights = Klines {
1 0.5 0.5 0.5 # L
36 0.0 0.0 0.0 # Gamma
30 0.0 0.5 0.5 # X
10 0.375 0.375 0.75 #K
35 0.0 0.0 0.0 # Gamma
}
}
ParserOptions {
ParserVersion = 4
}
=====================================================
# Input geometry
64 S
Si
1 1 -2.9487130000E-02 4.6082580000E-02 -7.7965000000E-03
2 1 1.0889385390E+01 2.6952983200E+00 2.6851953300E+00
3 1 1.0865623370E+01 5.4413451700E+00 5.5015257000E+00
4 1 1.0691597580E+01 8.1440238800E+00 8.1585569500E+00
5 1 2.7158302900E+00 -7.0057710000E-02 2.6540749100E+00
6 1 2.7676297400E+00 2.7158138600E+00 5.4168288800E+00
7 1 2.7238199600E+00 5.4284285100E+00 8.1526571600E+00
8 1 2.7779456700E+00 8.1229823900E+00 3.6968210000E-02
9 1 5.3930336900E+00 1.9005490000E-02 5.4017241600E+00
10 1 5.4348890200E+00 2.7446084800E+00 8.1279683100E+00
11 1 5.5462092100E+00 5.4720871000E+00 8.7391220000E-02
12 1 5.3414901800E+00 8.1557463100E+00 2.7288806400E+00
13 1 8.1473920100E+00 5.2395460000E-02 8.1886477100E+00
14 1 8.1638224100E+00 2.6765112700E+00 -3.0530450000E-02
15 1 8.2094121900E+00 5.4283998400E+00 2.6273788200E+00
16 1 8.1029311800E+00 8.0963328800E+00 5.4418031300E+00
17 1 2.7268415700E+00 2.7463805900E+00 -5.4477150000E-02
18 1 2.7252655800E+00 5.3892512000E+00 2.7608824900E+00
19 1 2.7591471200E+00 8.1219947800E+00 5.4230144000E+00
20 1 2.7550818800E+00 5.5631970000E-02 8.1537025900E+00
21 1 5.4326104700E+00 2.7407983900E+00 2.7321028300E+00
22 1 5.4082195300E+00 5.4191550600E+00 5.5158770700E+00
23 1 5.3774092300E+00 8.1982562900E+00 8.1093463300E+00
24 1 5.3803299800E+00 -3.1511880000E-02 -4.4996720000E-02
25 1 8.1635817900E+00 2.7298415100E+00 5.4841831200E+00
26 1 8.1089712200E+00 5.4168435700E+00 8.2024434100E+00
27 1 8.1424198000E+00 8.1298981100E+00 7.2693200000E-03
28 1 8.0590421300E+00 -1.2907045000E-01 2.6378045100E+00
29 1 4.2188170000E-02 2.7791679800E+00 8.1059886300E+00
30 1 1.9674380000E-02 5.4527295000E+00 3.3448270000E-02
31 1 -9.4614850000E-02 8.0629829400E+00 2.6944819100E+00
32 1 1.0840341090E+01 3.0179680000E-02 5.4037969000E+00
33 1 1.3216929000E+00 1.3316594100E+00 1.2613157400E+00
34 1 1.3871474900E+00 4.0825009100E+00 4.0597436700E+00
35 1 1.2952689900E+00 6.7912803000E+00 6.7863256300E+00
36 1 1.3301377400E+00 9.5809172000E+00 9.5086157500E+00
37 1 4.0887656900E+00 1.3838812000E+00 4.1018517000E+00
38 1 4.0671852800E+00 4.0743083300E+00 6.8230398000E+00
39 1 4.0753332100E+00 6.8110909100E+00 9.4522948800E+00
40 1 4.1132728100E+00 9.4801753600E+00 1.3279732400E+00
41 1 6.7976597400E+00 1.2796504500E+00 6.7708983100E+00
42 1 6.8326325700E+00 4.0330866400E+00 9.5184274500E+00
43 1 6.8233252400E+00 6.8470016900E+00 1.3560033000E+00
44 1 6.6644933900E+00 9.4852887400E+00 3.9799218000E+00
45 1 9.5230563400E+00 1.3010323700E+00 9.5213903400E+00
46 1 9.5313217700E+00 4.0887933300E+00 1.3152727800E+00
47 1 9.5047897800E+00 6.7404699700E+00 3.9851278300E+00
48 1 9.3677853700E+00 9.4371711700E+00 6.8550046700E+00
49 1 4.1148634800E+00 4.1136564000E+00 1.4472682900E+00
50 1 4.0511503000E+00 6.7886278200E+00 4.0528777500E+00
51 1 4.1256809500E+00 9.5118242000E+00 6.7484396400E+00
52 1 4.0856989500E+00 1.3711682200E+00 9.4398071300E+00
53 1 6.7706461800E+00 4.0334749700E+00 4.0747627200E+00
54 1 6.7186861700E+00 6.8005814200E+00 6.8538645300E+00
55 1 6.7479563000E+00 9.5281956600E+00 9.4586538800E+00
56 1 6.8187141700E+00 1.3326405900E+00 1.4106458100E+00
57 1 9.4856943500E+00 4.1381581400E+00 6.7607781400E+00
58 1 9.4717364400E+00 6.7711836200E+00 9.4952745800E+00
59 1 9.4896636900E+00 9.4140623200E+00 1.3199396200E+00
60 1 9.5309220700E+00 1.3073976500E+00 4.0415944000E+00
61 1 1.3792650900E+00 4.1001603500E+00 9.5119218300E+00
62 1 1.3616670700E+00 6.7352043900E+00 1.4389961300E+00
63 1 1.3543683800E+00 9.4876622000E+00 4.0610816200E+00
64 1 1.4497059300E+00 1.3959424600E+00 6.7845263700E+00
0.0000000000E+00 0.0000000000E+00 0.0000000000E+00
1.0852135050E+01 0.0000000000E+00 0.0000000000E+00
0.0000000000E+00 1.0852135050E+01 0.0000000000E+00
0.0000000000E+00 0.0000000000E+00 1.0852135050E+01
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