Investigate NEB changes

[ElliottKasoar]

Summary

In our dev tests, the results from NEB seem to change significantly:

FAILED tests/test_neb.py::test_neb - assert 17080.931940829614 == 8117.328587956959 ± 0.00811733
  
  comparison failed
  Obtained: 17080.931940829614
  Expected: 8117.328587956959 ± 0.00811733
FAILED tests/test_neb.py::test_set_calc - assert 17080.93194083008 == 8117.328587986063 ± 0.00811733
  
  comparison failed
  Obtained: 17080.93194083008
  Expected: 8117.328587986063 ± 0.00811733
FAILED tests/test_neb.py::test_neb_functions - assert 17080.93194083008 == 8117.328587986063 ± 0.00811733
  
  comparison failed
  Obtained: 17080.93194083008
  Expected: 8117.328587986063 ± 0.00811733
FAILED tests/test_neb.py::test_neb_plot - assert 0.478995869241885 == 0.4790452267999399 ± 4.8e-07

There may be changes to defaults.

Platform

Ubuntu 24.04

Version

0.8.7

Python version

Python 3.12