[Pw_forum] zero activation energy in NEB calculations
Manjusha Chugh
chughmanjusha at gmail.com
Thu Apr 17 08:58:40 CEST 2014
Dear all
I am doing NEB calculation to find the MEP between two states using
version neb-5.0.2. First, I want to get the path trajectory using no-CI
and after 10-15 iterations, if the path trajectory is stabilized, I will
use CI. But after 2nd iteration in my no-CI calculation, I am getting zero
activation energy. My system is Ga terminated surface of GaN(0001) and one
N atom is diffusing from one fcc site to another for which I am
calculating MEP.
Input and output files are attached. (The output is not complete since job
is still running). Can anyone clarify why activation energy is zero?
Thank you for your time
Manjusha
IIT Kanpur
India
Manjusha
Research Scholar
Deptt. of Chemistry
IIT Kanpur,Kanpur
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BEGIN
BEGIN_PATH_INPUT
&PATH
restart_mode = 'from_scratch',
string_method = 'neb',
nstep_path = 20,
ds = 1.0D0,
opt_scheme = "broyden",
num_of_images = 6,
k_max = 0.6D0,
k_min = 0.4D0,
path_thr = 0.1D0,
/
END_PATH_INPUT
BEGIN_ENGINE_INPUT
&CONTROL
prefix = "symm_NfccNEB",
outdir = "/home/pinku/tmp/",
pseudo_dir = "/home/pinku/pseudopotentials/",
/
&SYSTEM
ibrav = 0 ,
celldm(1) = 6.088,
nat = 53 ,
ntyp = 3 ,
ecutwfc = 60.0 ,
ecutrho = 480.0 ,
input_dft = 'PBE' ,
occupations = 'smearing',
smearing = 'methfessel-paxton' ,
degauss = 0.05
/
&ELECTRONS
conv_thr = 1.D-6,
mixing_mode = 'local-TF',
mixing_beta = 0.5D0
/
&IONS
ion_dynamics = 'bfgs'
/
ATOMIC_SPECIES
Ga 69.723 Ga.pbe-n-van.UPF
N 14.006 N.pbe-van_ak.UPF
H 1.0079 H.pz-vbc_075.UPF
K_POINTS (automatic)
2 2 1 0 0 0
CELL_PARAMETERS {hexagonal}
2.00 0.00 0.00
1.00 1.732 0.00
0.00 0.00 9.756
BEGIN_POSITIONS
FIRST_IMAGE
ATOMIC_POSITIONS {crystal}
H 0.000000000 0.000000000 0.196479930 0 0 0
H 0.000000000 0.500000000 0.196479930 0 0 0
H 0.500000000 0.000000000 0.196479930 0 0 0
H 0.500000000 0.500000000 0.196479930 0 0 0
N 0.000000000 0.000000000 0.229502345 0 0 0
N 0.000000000 0.500000000 0.229502345 0 0 0
N 0.500000000 0.000000000 0.229502345 0 0 0
N 0.500000000 0.500000000 0.229502345 0 0 0
Ga 0.166666666 0.166666666 0.249992062 0 0 0
Ga 0.166666666 0.666666666 0.249992062 0 0 0
Ga 0.666666666 0.166666666 0.249992062 0 0 0
Ga 0.666666666 0.666666666 0.249992062 0 0 0
N 0.166666666 0.166666666 0.312865782 0 0 0
N 0.166666666 0.666666666 0.312865782 0 0 0
N 0.666666666 0.166666666 0.312865782 0 0 0
N 0.666666666 0.666666666 0.312865782 0 0 0
Ga 0.000000000 0.000000000 0.333276902 0 0 0
Ga 0.000000000 0.500000000 0.333276902 0 0 0
Ga 0.500000000 0.000000000 0.333276902 0 0 0
Ga 0.500000000 0.500000000 0.333276902 0 0 0
N 0.000000000 0.000000000 0.396156112 0 0 0
N 0.000000000 0.500000000 0.396156112 0 0 0
N 0.500000000 0.000000000 0.396156112 0 0 0
N 0.500000000 0.500000000 0.396156112 0 0 0
Ga 0.166666666 0.166666666 0.416443231 0 0 0
Ga 0.166666666 0.666666666 0.416443231 0 0 0
Ga 0.666666666 0.166666666 0.416443231 0 0 0
Ga 0.666666666 0.666666666 0.416443231 0 0 0
N 0.166666666 0.166666666 0.479347469 0 0 0
N 0.166666666 0.666666666 0.479347469 0 0 0
N 0.666666666 0.166666666 0.479347469 0 0 0
N 0.666666666 0.666666666 0.479347469 0 0 0
Ga 0.000000000 0.000000000 0.499538888
Ga 0.000000000 0.500000000 0.499538888
Ga 0.500000000 0.000000000 0.499538888
Ga 0.500000000 0.500000000 0.499538888
N 0.000000000 0.000000000 0.562604521
N 0.000000000 0.500000000 0.562604521
N 0.500000000 0.000000000 0.562604521
N 0.500000000 0.500000000 0.562604521
Ga 0.166666666 0.166666666 0.582839633
Ga 0.166666666 0.666666666 0.582839633
Ga 0.666666666 0.166666666 0.582839633
Ga 0.666666666 0.666666666 0.582839633
N 0.166666666 0.166666666 0.646698312
N 0.166666666 0.666666666 0.646698312
N 0.666666666 0.166666666 0.646698312
N 0.666666666 0.666666666 0.646698312
Ga 0.000000000 0.000000000 0.667589406
Ga 0.000000000 0.500000000 0.667589406
Ga 0.500000000 0.000000000 0.667589406
Ga 0.500000000 0.500000000 0.667589406
N 0.333333333 0.333333333 0.731223019
LAST_IMAGE
ATOMIC_POSITIONS {crystal}
H 0.000000000 0.000000000 0.196479930 0 0 0
H 0.000000000 0.500000000 0.196479930 0 0 0
H 0.500000000 0.000000000 0.196479930 0 0 0
H 0.500000000 0.500000000 0.196479930 0 0 0
N 0.000000000 0.000000000 0.229502345 0 0 0
N 0.000000000 0.500000000 0.229502345 0 0 0
N 0.500000000 0.000000000 0.229502345 0 0 0
N 0.500000000 0.500000000 0.229502345 0 0 0
Ga 0.166666666 0.166666666 0.249992062 0 0 0
Ga 0.166666666 0.666666666 0.249992062 0 0 0
Ga 0.666666666 0.166666666 0.249992062 0 0 0
Ga 0.666666666 0.666666666 0.249992062 0 0 0
N 0.166666666 0.166666666 0.312865782 0 0 0
N 0.166666666 0.666666666 0.312865782 0 0 0
N 0.666666666 0.166666666 0.312865782 0 0 0
N 0.666666666 0.666666666 0.312865782 0 0 0
Ga 0.000000000 0.000000000 0.333276902 0 0 0
Ga 0.000000000 0.500000000 0.333276902 0 0 0
Ga 0.500000000 0.000000000 0.333276902 0 0 0
Ga 0.500000000 0.500000000 0.333276902 0 0 0
N 0.000000000 0.000000000 0.396156112 0 0 0
N 0.000000000 0.500000000 0.396156112 0 0 0
N 0.500000000 0.000000000 0.396156112 0 0 0
N 0.500000000 0.500000000 0.396156112 0 0 0
Ga 0.166666666 0.166666666 0.416443231 0 0 0
Ga 0.166666666 0.666666666 0.416443231 0 0 0
Ga 0.666666666 0.166666666 0.416443231 0 0 0
Ga 0.666666666 0.666666666 0.416443231 0 0 0
N 0.166666666 0.166666666 0.479347469 0 0 0
N 0.166666666 0.666666666 0.479347469 0 0 0
N 0.666666666 0.166666666 0.479347469 0 0 0
N 0.666666666 0.666666666 0.479347469 0 0 0
Ga 0.000000000 0.000000000 0.499538888
Ga 0.000000000 0.500000000 0.499538888
Ga 0.500000000 0.000000000 0.499538888
Ga 0.500000000 0.500000000 0.499538888
N 0.000000000 0.000000000 0.562604521
N 0.000000000 0.500000000 0.562604521
N 0.500000000 0.000000000 0.562604521
N 0.500000000 0.500000000 0.562604521
Ga 0.166666666 0.166666666 0.582839633
Ga 0.166666666 0.666666666 0.582839633
Ga 0.666666666 0.166666666 0.582839633
Ga 0.666666666 0.666666666 0.582839633
N 0.166666666 0.166666666 0.646698312
N 0.166666666 0.666666666 0.646698312
N 0.666666666 0.166666666 0.646698312
N 0.666666666 0.666666666 0.646698312
Ga 0.000000000 0.000000000 0.667589406
Ga 0.000000000 0.500000000 0.667589406
Ga 0.500000000 0.000000000 0.667589406
Ga 0.500000000 0.500000000 0.667589406
N 0.833333333 0.333333333 0.731223019
END_POSITIONS
END_ENGINE_INPUT
END
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Program NEB v.5.0.2 starts on 15Apr2014 at 9:23:11
This program is part of the open-source Quantum ESPRESSO suite
for quantum simulation of materials; please cite
"P. Giannozzi et al., J. Phys.:Condens. Matter 21 395502 (2009);
URL http://www.quantum-espresso.org",
in publications or presentations arising from this work. More details at
http://www.quantum-espresso.org/quote.php
Parallel version (MPI), running on 18 processors
R & G space division: proc/nbgrp/npool/nimage = 18
Warning: card &IONS ignored
Warning: card ION_DYNAMICS = 'BFGS' ignored
Warning: card / ignored
IMPORTANT: XC functional enforced from input :
Exchange-correlation = PBE ( 1 4 3 4 0)
EXX-fraction = 0.00
Any further DFT definition will be discarded
Please, verify this is what you really want
file H.pz-vbc_075.UPF: wavefunction(s) 1S renormalized
Warning: card &IONS ignored
Warning: card ION_DYNAMICS = 'BFGS' ignored
Warning: card / ignored
IMPORTANT: XC functional enforced from input :
Exchange-correlation = PBE ( 1 4 3 4 0)
EXX-fraction = 0.00
Any further DFT definition will be discarded
Please, verify this is what you really want
file H.pz-vbc_075.UPF: wavefunction(s) 1S renormalized
initial path length = 6.0880 bohr
initial inter-image distance = 1.2176 bohr
string_method = neb
restart_mode = from_scratch
opt_scheme = broyden
num_of_images = 6
nstep_path = 10
CI_scheme = no-CI
first_last_opt = F
use_freezing = F
ds = 1.0000 a.u.
k_max = 0.6000 a.u.
k_min = 0.4000 a.u.
suggested k_max = 0.6169 a.u.
suggested k_min = 0.4112 a.u.
path_thr = 0.1000 eV / A
------------------------------ iteration 1 ------------------------------
tcpu = 0.3 self-consistency for image 1
tcpu = 3754.0 self-consistency for image 2
tcpu = 9381.5 self-consistency for image 3
tcpu = 14810.5 self-consistency for image 4
tcpu = 20471.4 self-consistency for image 5
tcpu = 26323.9 self-consistency for image 6
activation energy (->) = 0.036522 eV
activation energy (<-) = 0.036521 eV
image energy (eV) error (eV/A) frozen
1 -64917.3691663 3.118784 T
2 -64917.3612196 3.130575 F
3 -64917.3326471 2.778883 F
4 -64917.3326448 2.778657 F
5 -64917.3612169 3.130575 F
6 -64917.3691661 3.119165 T
path length = 6.088 bohr
inter-image distance = 1.218 bohr
------------------------------ iteration 2 ------------------------------
tcpu = 30737.4 self-consistency for image 2
tcpu = 34000.0 self-consistency for image 3
tcpu = 37194.2 self-consistency for image 4
tcpu = 40348.8 self-consistency for image 5
activation energy (->) = 0.000000 eV
activation energy (<-) = 0.000000 eV
image energy (eV) error (eV/A) frozen
1 -64917.3691663 3.118784 T
2 -64917.6300552 3.984277 F
3 -64917.5735247 2.541398 F
4 -64917.5729921 2.541976 F
5 -64917.6303398 3.977213 F
6 -64917.3691661 3.119165 T
path length = 6.098 bohr
inter-image distance = 1.220 bohr
------------------------------ iteration 3 ------------------------------
tcpu = 43492.2 self-consistency for image 2
tcpu = 47366.5 self-consistency for image 3
tcpu = 50716.1 self-consistency for image 4
tcpu = 54090.0 self-consistency for image 5
activation energy (->) = 0.000000 eV
activation energy (<-) = 0.000000 eV
image energy (eV) error (eV/A) frozen
1 -64917.3691663 3.118784 T
2 -64918.0579044 2.757654 F
3 -64917.9360578 2.187571 F
4 -64917.9356208 2.187656 F
5 -64918.0580502 2.758018 F
6 -64917.3691661 3.119165 T
path length = 6.164 bohr
inter-image distance = 1.233 bohr
------------------------------ iteration 4 ------------------------------
tcpu = 57928.4 self-consistency for image 2
tcpu = 62313.7 self-consistency for image 3
tcpu = 66138.2 self-consistency for image 4
tcpu = 69956.4 self-consistency for image 5
activation energy (->) = 0.000000 eV
activation energy (<-) = 0.000000 eV
image energy (eV) error (eV/A) frozen
1 -64917.3691663 3.118784 T
2 -64918.6842995 2.822266 F
3 -64918.3336882 1.072720 F
4 -64918.3335107 1.073567 F
5 -64918.6849020 2.820651 F
6 -64917.3691661 3.119165 T
path length = 6.426 bohr
inter-image distance = 1.285 bohr
------------------------------ iteration 5 ------------------------------
tcpu = 74166.9 self-consistency for image 2
tcpu = 78478.8 self-consistency for image 3
tcpu = 82233.7 self-consistency for image 4
tcpu = 85980.2 self-consistency for image 5
activation energy (->) = 0.000000 eV
activation energy (<-) = 0.000000 eV
image energy (eV) error (eV/A) frozen
1 -64917.3691663 3.118784 T
2 -64919.2464153 2.881492 F
3 -64918.4311601 1.738661 F
4 -64918.4310973 1.738617 F
5 -64919.2471462 2.878638 F
6 -64917.3691661 3.119165 T
path length = 6.924 bohr
inter-image distance = 1.385 bohr
------------------------------ iteration 6 ------------------------------
tcpu = 90183.5 self-consistency for image 2
tcpu = 94229.5 self-consistency for image 3
tcpu = 97420.5 self-consistency for image 4
tcpu = 100612.6 self-consistency for image 5
activation energy (->) = 0.000000 eV
activation energy (<-) = 0.000000 eV
image energy (eV) error (eV/A) frozen
1 -64917.3691663 3.118784 T
2 -64919.6863336 2.357326 F
3 -64918.3306026 3.752568 F
4 -64918.3307659 3.754808 F
5 -64919.6865281 2.355640 F
6 -64917.3691661 3.119165 T
path length = 7.684 bohr
inter-image distance = 1.537 bohr
------------------------------ iteration 7 ------------------------------
tcpu = 104646.2 self-consistency for image 2
tcpu = 108199.4 self-consistency for image 3
tcpu = 111993.6 self-consistency for image 4
tcpu = 115757.4 self-consistency for image 5
activation energy (->) = 0.000000 eV
activation energy (<-) = 0.000000 eV
image energy (eV) error (eV/A) frozen
=------------------------------------------------------------------------------=
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