[Pw_forum] Intermediate images in NEB
fratesi at mater.unimib.it
Tue Oct 2 17:57:28 CEST 2007
| However, there are case when it would be desirable to use EXACTLY that
| initial guess, for example in case of interpolation
| through intermediate values of a torsional angle...
| That's the origin of my concern. Maybe it would not be a bad idea to
| add this option...
at once I was also in the need of specifying EXACTLY a given initial path.
The reason, in my case, was that I wanted to merge two paths from
different calculations in a single one. Of course, I didn't want a
re-interpolation to spoil the accuracy already reached.
Then, I build the path file "by hand" (but awk or the like is helpful).
That's not that hard.
One possibility for you could be to edit the interpolated path file
which you get with nstep=0, and replace the coordinate of some images with
the ones you want. Then you can restart from this path file.
The real problem, in my opinion, is that a path build up this way will
generally have images not at the right spacing, therefore
feeling too much the springs in the direction parallel to the path. This
could require a few additional optimization steps, and possibly compensate
Another solution could be to generate a set of path files linking the
various intermediate images, to merge them, and finally to start the
optimization of this merged path.
I feel that could work better than my previous suggestion, because
possibly no image would feel to strong springs, if the initial spacings of
the various paths is comparable.
Hope this helps more than confuses
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