## questions on solid state neb

Python framework for working with atomic configurations, potentials, and algorithms.

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hummerwjl
Posts: 1
Joined: Tue Sep 03, 2019 9:14 pm

### questions on solid state neb

Hi all,

I'm working on solid state neb and I've few questions:

1. time step in ssneb is default set at 0.1. I'm wondering is this the time step of translation matrix? What's the physical meaning of it?

2. exts.dat and extsss.dat file are generated by neresults.pl after ssneb calculation, which do not appear in regular neb. Can you please explain each column of the two files?

Best,
lappyexpert
Posts: 1
Joined: Sat Mar 18, 2023 8:23 am

### Re: questions on solid state neb

The exts.dat and extsss.dat files are generated by neresults.pl after an SSNEB (string method with the nudged elastic band) calculation in the VASP (Vienna Ab initio Simulation Package) software. These files contain information about the intermediate images along the reaction pathway.

The exts.dat file contains information about the electronic structure properties, such as the electronic energy, eigenvalues, and occupation numbers, for each intermediate image. The columns in the exts.dat file are:

Column 1: The image number
Column 2: The electronic energy of the image
Column 3-6: The x, y, and z coordinates of the centroid of the image
Column 7: The number of electronic bands
Column 8: The number of k-points
Column 9: The maximum eigenvalue
Column 10: The minimum eigenvalue
Column 11: The maximum occupation number
Column 12: The minimum occupation number

The extsss.dat file contains information about the structural properties, such as the atomic positions, forces, and stress tensors, for each intermediate image. The columns in the extsss.dat file are:

Column 1: The image number
Column 2: The Cartesian x-coordinate of the first atom
Column 3: The Cartesian y-coordinate of the first atom
Column 4: The Cartesian z-coordinate of the first atom
Column 5: The x-component of the force acting on the first atom
Column 6: The y-component of the force acting on the first atom
Column 7: The z-component of the force acting on the first atom
Column 8-10: The Cartesian x, y, and z components of the stress tensor for the image
Columns 11-13: The Cartesian x, y, and z coordinates of the second atom
Columns 14-16: The Cartesian x, y, and z components of the force acting on the second atom
Columns 17-19: The Cartesian x, y, and z components of the stress tensor for the second atom, and so on for the remaining atoms.
These files can be useful for analyzing the electronic and structural properties of the intermediate images along the reaction pathway, and for visualizing the reaction mechanism.