QuantumATK Forum
QuantumATK => General Questions and Answers => Topic started by: coraline on October 16, 2020, 06:52
-
Dear all,
I am running the NEB calculation for oxygen moving in a bismuth oxide lattice. Suprisingly, it returns me with the activation energy equal zero like this.
| NEB Optimization using the LBFGS optimizer |
+------------------------------------------------------------------------------+
| Iteration Step Length Max. Force Max. Energy Image Max. Energy |
| (Ang) (eV/Ang) (eV) |
+------------------------------------------------------------------------------+
| 0 0.000e+00 2.042e+00 4 1.038190 |
| 1 1.460e-01 1.527e+00 4 0.661239 |
| 2 5.897e-02 4.990e-01 4 0.447937 |
| 3 9.809e-02 4.334e-01 4 0.299187 |
| 4 7.313e-02 9.043e-01 4 0.212851 |
| 5 1.039e-01 5.077e-01 4 0.125279 |
| 6 4.990e-02 2.254e-01 4 0.076003 |
| 7 3.500e-02 2.416e-01 4 0.046288 |
| 8 6.624e-02 2.665e-01 4 0.015152 |
| 9 7.631e-02 2.870e-01 0 0.000000 |
| 10 3.436e-02 1.971e-01 0 0.000000 |
| 11 3.680e-02 2.193e-01 0 0.000000 |
| 12 5.603e-02 2.288e-01 0 0.000000 |
| 13 6.008e-02 1.451e-01 0 0.000000 |
| 14 3.966e-02 1.537e-01 0 0.000000 |
| 15 3.536e-02 1.405e-01 0 0.000000 |
| 16 3.526e-02 1.247e-01 0 0.000000 |
| 17 2.366e-02 8.175e-02 0 0.000000 |
| 18 2.393e-02 9.213e-02 0 0.000000 |
| 19 3.350e-02 1.147e-01 0 0.000000 |
| 20 3.306e-02 1.099e-01 0 0.000000 |
| 21 2.371e-02 1.107e-01 0 0.000000 |
| 22 1.409e-02 9.503e-02 0 0.000000 |
| 23 1.235e-02 7.594e-02 0 0.000000 |
| 24 1.256e-02 9.409e-02 0 0.000000 |
| 25 2.238e-02 1.023e-01 0 0.000000 |
| 26 3.851e-02 1.285e-01 0 0.000000 |
| 27 1.008e-01 2.813e-01 0 0.000000 |
| 28 7.897e-03 2.026e-01 0 0.000000 |
| 29 2.958e-02 1.504e-01 0 0.000000 |
| 30 2.162e-02 1.437e-01 0 0.000000 |
| 31 1.036e-02 1.164e-01 0 0.000000 |
| 32 1.354e-02 9.935e-02 0 0.000000 |
| 33 2.134e-02 1.151e-01 0 0.000000 |
| 34 2.581e-02 1.108e-01 0 0.000000 |
| 35 1.162e-02 9.312e-02 0 0.000000 |
| 36 6.608e-03 7.186e-02 0 0.000000 |
| 37 6.804e-03 4.837e-02 0 0.000000 |
+------------------------------------------------------------------------------+
| NEB optimization converged after 37 steps. |
+------------------------------------------------------------------------------+
<NL.CommonConcepts.Configurations.NudgedElasticBand.NudgedElasticBand object at 0x2b33e99594a8>
Is this because of some sort of error from my set up, or is there any other explanation for this situation?
-
During the NEB optimization, your image with the max energy barrier has been changed from number 4 to 0. After changing into image 0 (initial point), it shows 0 in energy barrier. You can compare without optimization and with optimization. If you use R2020-09 version, NEB hdf5 includes both objects(NudgedElasticBand_0:before optimization, NudgedElasticBand_1: after optimization). Can you check whether you setup a reasonable NEB path?
-
Yes, I check that it a reasonable path. Some how the problem was solved when I change to another functional.
-
Thanks for your update. Good to know about it.