The files in folder 1 are HRTEM images, Image Simulations and Structure models used to produce Figures 1a-h. The images are are best visualised using the free offline version of Gatan Microscopy Suite 3 (i.e. GMS3) incorporating the EELS/EFTEM Suite (i.e. useful for Figure 3). This is free to download at https://www.gatan.com/enabling-researcher-access-gms-3-during-covid-19-lab-closures
(accessed 28-7-21).
Structures (in protein database *.pdb format) can be visualised using freeware or open source utilities such as Molmil (http://gjbekker.github.io/molmil/) or Rasmol (http://www.openrasmol.org)

The files in folder 2 are HRTEM images, Image Simulations, Struture models and HAADF images used to produce Figures 2a-g. The images are are best visualised using the free offline version of Gatan Microscopy Suite 3 (i.e. GMS3) incorporating the EELS/EFTEM Suite (i.e. useful for Figure 3). This is free to download at https://www.gatan.com/enabling-researcher-access-gms-3-during-covid-19-lab-closures
(accessed 28-7-21).
Structures (in protein database *.pdb format) can be visualised using freeware or open source utilities such as Molmil (http://gjbekker.github.io/molmil/) or Rasmol (http://www.openrasmol.org)

The files in folder 3 are the raw HAADF images, Spectrum Images and EELS spectra used to produce Figures 3a-i. Note that, due to the cumbersome and specialised nature of the data, these are best visualised using the free offline version of Gatan Microscopy Suite 3 (i.e. GMS3) incorporating the EELS/EFTEM Suite. This is free to download at https://www.gatan.com/enabling-researcher-access-gms-3-during-covid-19-lab-closures
(accessed 28-7-21).
Structures (in protein database *.pdb format) can be visualised using freeware or open source utilities such as Molmil (http://gjbekker.github.io/molmil/) or Rasmol (http://www.openrasmol.org)

The files in folder 4 were used in the production of Figs. 4a-c and include The calculated Energy/Ion Pair with Helical Pitch (Fig. 4a folder); Model structures for 1D, 2X1 and 2X2 CsI@CNTs of various diameters and the calculated formation enthalpies for these structures (Fig. 4b folder); Calculated charges for these and 1D_I@CNT structures (Fig. 4c folder).

The files in folder 5 are HRTEM images, Structure models and HAADF images used to produce Figures 5a-g. The images are are best visualised using the free offline version of Gatan Microscopy Suite 3 (i.e. GMS3) incorporating the EELS/EFTEM Suite (i.e. useful for Figure 3). This is free to download at https://www.gatan.com/enabling-researcher-access-gms-3-during-covid-19-lab-closures
(accessed 28-7-21).
Structures (in protein database *.pdb format) can be visualised using freeware or open source utilities such as Molmil (http://gjbekker.github.io/molmil/) or Rasmol (http://www.openrasmol.org)

The files in folder 6 contain the raw spectroscopy data used to produce Figures 6a-d and include the Raman Data (Fig6a folder), the optical absorption spectra (Fig6b folder) and also the Photoluminescence (i.e. PL) data (Fig6c-d folder). Note that Fig6c was produced by taking sections through the PL data at 650 nm (top) and 575 nm (bottom) respectively (i.e. see dotted lines on Figure 6d, main manuscript)

• Other