[QE-users] Error with IFC generation
Aliya Qureshi
aliyaqureshi at umass.edu
Wed Apr 24 19:40:42 CEST 2019
On 2019-04-23 13:52, Aliya Qureshi wrote:
> Hello QE Users,
>
> I am trying to generate 3IFC file for Silicon and is facing some
> issues with it. The 3ifc generated don’t decay after a point and
> because of which I am getting incorrect values for calculation
> following it.
>
> Using, shengBTE I generate my displaced super-cell files, and then use
> these as input files by Quantum Espresso for calculating the forces
> arising from atomic displacements. Then, I generate the force
> constants using those files. But, the force constants which I am
> getting tends not to decay after a point.
>
> Attached is a plot for the 3IFC generated. The horizontal axes is the
> sum of the three distances between the atoms defining a triplet and
> the vertical axis is the Frobenius norm of the 3x3x3 matrix of
> third-order force constants for that triplet.
>
> Can you please guide me with this, I am a new user to QE, any guidance
> is appreciated.
> Thank You.
>
>
> Best,
> Aliya Qureshi
> NanoEnergy and Thermophysics Lab
> Electrical and Computer Engineering Dept.
> University of Massachusetts Amherst
>
>
> ##########################################################################################
> Below are the files in order:
> 1. The input file of unit cell
> 2. A template input file for supercell calculations
> 3. DISP.si_supercelltemplete.in (snippet)
> 4. DISP.si_supercelltemplete.out (snippet)
> 5. Snip from 3IFC file
>
>
> *******************Si.scf_thirdorder.in*******************************
>
> &CONTROL
> calculation='scf', prefix='Si', restart_mode='from_scratch',
> tstress = .true., tprnfor = .true.,
> /
> &SYSTEM
> ibrav=2, celldm(1)=10.263, nat=2, ntyp=1, ecutwfc=38.0
> ecutrho=151.0
> /
> &ELECTRONS
> conv_thr=1.0d-9,
> /
> ATOMIC_SPECIES
> Si 28.0855 Si.pbe-n-kjpaw_psl.0.1.UPF
> ATOMIC_POSITIONS crystal
> Si 0.00 0.00 0.00
> Si 0.25 0.25 0.25
> K_POINTS gamma
>
> ***********************************Si_supercelltemplete.in***************************
> &CONTROL
> calculation='scf', prefix='Si', tstress = .true.' tprnfor = .true.,
> outdir = '/project/si_supercelltemplete##NUMBER##
> pseudo_dir = '/home/aq26a/qe/q-e-qe-6.2.1/pseudo/'
> /
> &SYSTEM
> ibrav=0, nat=##NATOMS##, ntyp=1, ecutwfc=38.0 ecutrho=151.0
> /
> &ELECTRONS
> conv_thr = 1.0d-9
> /
> ATOMIC_SPECIES
> Si 28.0855 Si.pbe-n-kjpaw_psl.0.1.UPF
> ##COORDINATES##
> K_POINTS gamma
> ##CELL##
>
>
>
> *******************************DISP.si_supercelltemplete.in***************************
> &CONTROL
> calculation='scf',
> prefix='Si',
> tstress = .true.' tprnfor = .true., outdir =
> '/project/si_supercelltemplete1' pseudo_dir =
> '/home/aq26a/qe/q-e-qe-6.2.1/pseudo/'
> /
> &SYSTEM
> ibrav=0, nat=128, ntyp=1, ecutwfc=38.0 ecutrho=151.0 /
> &ELECTRONS
> conv_thr = 1.0d-9
> /
> ATOMIC_SPECIES
> Si 28.0855 Si.pbe-n-kjpaw_psl.0.1.UPF
> ATOMIC_POSITIONS crystal
> Si -0.00092064996812095 0 0.00092064996812095
> Si 0.0625 0.0625 0.0625
> Si 0.25 0 0
> Si 0.3125 0.0625 0.0625
> Si 0.5 0 0
> Si 0.5625 0.0625 0.0625
> Si 0.75 0 0
> Si 0.8125 0.0625 0.0625
> Si 0 0.25 0
> Si 0.0625 0.3125 0.0625
> .
> .
> .
> .
> Si 0.75 0.75 0.75
> Si 0.8125 0.8125 0.8125
> K_POINTS gamma
> CELL_PARAMETERS angstrom
> -10.8618914313439 0 10.8618914313439
> 0 10.8618914313439 10.8618914313439
> -10.8618914313439 10.8618914313439 0
>
>
> ****************************DISP.si_supercelltemplete.out******************************
> .
> .
> .
> 5.0482 5.0482 5.0482 5.0482 5.0482 5.4882 5.4882 5.4882
> 5.4882 5.4882 5.4882 5.4882 5.4882 5.4882 5.4882
> 5.4882
> 5.4882 5.4882 5.4882 5.4882 5.4882 6.2518 6.2518
> 6.2518
>
> highest occupied level (ev): 6.2518
>
> ! total energy = -5980.18082331 Ry
> Harris-Foulkes estimate = -5980.18082330 Ry
> estimated scf accuracy < 1.6E-10 Ry
>
> total all-electron energy = -74248.451930 Ry
>
> The total energy is the sum of the following terms:
>
> one-electron contribution = 367.11806762 Ry
> hartree contribution = 71.80268742 Ry
> xc contribution = -785.10766678 Ry
> ewald contribution = -1074.94517644 Ry
> one-center paw contrib. = -4559.04873514 Ry
>
> convergence has been achieved in 13 iterations
>
> Forces acting on atoms (cartesian axes, Ry/au):
>
> atom 1 type 1 force = 0.00000000 0.00000000
> -0.00000000
> atom 2 type 1 force = 0.00000010 -0.00000010
> -0.00000010
> atom 3 type 1 force = 0.00000002 -0.00000014
> -0.00000002
> .
> .
> .
>
>
> ***********************3IFC
> file********************************************
> Snippet from 3ifc file: where the structure description is as:
> • A blank line
> • A 1-based sequential index
> • A line with the Cartesian coordinates of the second unit cell in
> Å
> • A line with the Cartesian coordinates of the third unit cell in
> Å
> • A line with the 1-based indices of the three atoms involved, each
> from 1 to natoms
> • 27 lines, each of which starts with a tern of integers specifying
> three Cartesian axes and is completed by a force constant in
> eV/Å<sup>3</sup>. The last element of the tern changes first
>
> 1
> 0.0000000000e+00 0.0000000000e+00 0.0000000000e+00
> 0.0000000000e+00 0.0000000000e+00 0.0000000000e+00
> 1 1 1
> 1 1 1 0.0000000000e+00
> 1 1 2 0.0000000000e+00
> 1 1 3 0.0000000000e+00
> 1 2 1 0.0000000000e+00
> 1 2 2 0.0000000000e+00
> 1 2 3 -3.1541466075e+01
> 1 3 1 0.0000000000e+00
> 1 3 2 -3.1541466075e+01
> 1 3 3 0.0000000000e+00
> 2 1 1 0.0000000000e+00
> 2 1 2 0.0000000000e+00
> 2 1 3 -3.1541466075e+01
> 2 2 1 0.0000000000e+00
> 2 2 2 0.0000000000e+00
> 2 2 3 0.0000000000e+00
> 2 3 1 -3.1541466075e+01
> 2 3 2 0.0000000000e+00
> 2 3 3 0.0000000000e+00
> 3 1 1 0.0000000000e+00
> 3 1 2 -3.1541466075e+01
> 3 1 3 0.0000000000e+00
> 3 2 1 -3.1541466075e+01
> 3 2 2 0.0000000000e+00
> 3 2 3 0.0000000000e+00
> 3 3 1 0.0000000000e+00
> 3 3 2 0.0000000000e+00
> 3 3 3 0.0000000000e+00
>
> 2
> 0.0000000000e+00 0.0000000000e+00 0.0000000000e+00
> 0.0000000000e+00 0.0000000000e+00 0.0000000000e+00
> 1 1 2
> 1 1 1 2.9619109574e+00
> 1 1 2 -5.9122449335e+00
> 1 1 3 -5.9122449335e+00
> 1 2 1 -6.1143664229e+00
> 1 2 2 6.1143664229e+00
> 1 2 3 7.9842098089e+00
> 1 3 1 -6.1143664229e+00
> 1 3 2 7.9842098089e+00
> 1 3 3 6.1143664229e+00
> 2 1 1 -6.1143664229e+00
> 2 1 2 6.1143664229e+00
> 2 1 3 7.9842098089e+00
> 2 2 1 5.9122449335e+00
> 2 2 2 -2.9619109574e+00
> 2 2 3 -5.9122449335e+00
> 2 3 1 7.9842098089e+00
> 2 3 2 -6.1143664229e+00
> 2 3 3 -6.1143664229e+00
> 3 1 1 -6.1143664229e+00
> 3 1 2 7.9842098089e+00
> 3 1 3 6.1143664229e+00
> 3 2 1 7.9842098089e+00
> 3 2 2 -6.1143664229e+00
> 3 2 3 -6.1143664229e+00
> 3 3 1 5.9122449335e+00
> 3 3 2 -5.9122449335e+00
> 3 3 3 -2.9619109574e+00
>
> 3
> 0.0000000000e+00 0.0000000000e+00 0.0000000000e+00
> -2.7154728578e+00 0.0000000000e+00 2.7154728578e+00
> 1 1 1
> 1 1 1 1.5105231662e-01
> 1 1 2 -5.4158751476e-02
> 1 1 3 -1.9328736602e-01
> 1 2 1 -5.1574972130e-02
> 1 2 2 -1.1306403226e-01
> 1 2 3 -6.3804775915e-02
> 1 3 1 -2.2537028746e-01
> 1 3 2 4.5126069497e-03
> 1 3 3 2.2537028746e-01
> 2 1 1 -5.1574972130e-02
> 2 1 2 -1.1306403226e-01
> 2 1 3 -6.3804775915e-02
> 2 2 1 -1.2593092626e-01
> 2 2 2 1.5722908765e-02
> 2 2 3 1.2593092626e-01
> 2 3 1 -6.3804775915e-02
> 2 3 2 1.1306403226e-01
> 2 3 3 -5.1574972130e-02
> 3 1 1 -2.2537028746e-01
> 3 1 2 4.5126069497e-03
> 3 1 3 2.2537028746e-01
> 3 2 1 -6.3804775915e-02
> 3 2 2 1.1306403226e-01
> 3 2 3 -5.1574972130e-02
> 3 3 1 1.9328736602e-01
> 3 3 2 -5.4158751476e-02
> 3 3 3 -1.5105231662e-01
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