This repository contains the relevant data corresponding to the article "Intrinsic flexibility of the EMT zeolite framework under pressure".
This readme file contains an explanation of the contents of the directories within this folder, and describes the information within the contained files.


- file "EMT structure figure.cmdx"
A Crystalmaker X file that contains the structure of the EMT framework containing the 18C6 molecule by Baerlocher et al. (Ref [28] in the article). This file was used to produce Figure 1, in addition to being the input .cif files for the GASP simulated flexibility windows.




1) Directory "High-Pressure Powder X-ray Diffraction"
-----------------------------------------------------

Contains all the data relevant to the "High-Pressure Powder X-ray Diffraction" section of the article. Contents are listed below:

- file "EMT_data.opj"
an origin project file, containing all relevant unit cell parameters of the samples, in addition to the graphs used to make the figures in the article.

- file "EMT_filledvsempty_flexibilitywindows.xlsx"
an excel spreadsheet, containing the unit cell parameters and pressures for both the empty and filled zeolite EMC-2 samples. Also listed are the filenames for each pressure point, corresponding to the .xy files in the directories explained below. In addition, the spreadsheet contains the GASP simulated flexibility windows.

- file "EMTe_PASCal_below2.2.pdf"
a pdf output file produced from the PASCal webtool by Cliffe and Goodwin (Ref [36] in the article) for the empty zeolite EMC-2. This contains the bulk modulus and pressure derivative used in the article. The bottom of the file includes the input data used.

- file "EMTf_PASCal_below2.2.pdf"
a pdf output file produced from the PASCal webtool by Cliffe and Goodwin (Ref [36] in the article) for the empty zeolite EMC-2. This contains the bulk modulus and pressure derivative used in the article. The bottom of the file includes the input data used.


1.1) Directory "EMT_empty"
--------------------------

Contains the X-ray diffraction data for the empty zeolite EMC-2 sample. These are .xy files.


1.2) Directory "EMT_filled"
---------------------------

Contains the X-ray diffraction data for the filled zeolite EMC-2 sample. These are .xy files.


1.3) Directory "Other_EMT_samples_SI"
-------------------------------------

Contains the x-ray diffraction data relevant to the zeolite EMC-2 samples shown in the Supplementary Information (SI). The contents are as follows:

- file "EMT_hydrated_new.xlsx"
an excel spreadsheet containing the unit cell parameters for the hydrated empty zeolite EMC-2 sample measured on the ID15B beamline at the ESRF, France, using daphne oil as a non-penetrating pressure transmitting medium.

- file "EMT_empty_silicone_oil.xlsx"
an excel spreadsheet containing the unit cell parameters for the empty zeolite EMC-2 sample measured on the ID27 beamline at the ESRF, France, using silicone oil as a non-penetrating pressure transmitting medium.





2) Directory "Computational Modelling"
--------------------------------------

Contains all the data relevant to the "Computational Modelling" section of the article.


2.1) Optimised Structures
-------------------------

Optimised structures of faujasite (FAU) and zeolite EMC-2 (EMT) are provided in the Vienna Ab initio Simulation Package (VASP) POSCAR format (".vasp" file extension).[1]
As explained in the manuscript, a total of four optimised structures were generated as follows: (1) using the PBEsol exchange-correlation functional, (2) using PBEsol with the DFT-D3 dispersion correction (PBEsol+D3), and (3/4) using PBEsol and PBEsol+D3 with a continuum solvent of water (H2O) included using the VASPsol model.
These files can be read in a text editor and visualised using a number of software packages, for example the free VESTA program.[2]

2.2) Mechanical Properties
--------------------------

Calculated energy/volume curves (equations of state) for FAU and EMT and the full elastic-constant matrix of FAU are provided as plain-text comma-separated values (CSV) files.
The content of these files can be viewed in a text editor or opened in a spreadsheet package such as Microsoft Excel or Origin.

2.3) Phonon calculations
------------------------

Data from the lattice-dynamics calculations performed on the optimised FAU and EMT structures with PBEsol+D3 are provided in three subfolders named "PBEsol+D3-FAU-Prim-Phonon", "PBEsol+D3-FAU-Conv-Phonon", and "PBEsol+D3-EMT-Phonon".
The force-constant calculations and post processing to obtain the phonon frequencies/eigenvectors, density-of-states curves and temperature-dependent Helmholtz free energy were performed using the Phonopy package,[3] and infrared (IR) spectra were simulated using the Phonopy-Spectroscopy code.[4]
Calculations on FAU were performed using force constants calculated in the primitive ("Prim") and conventional ("Conv") cells, which were found to produce very similar results.
For information about the format and content of the various files in the calculation folders, users are referred to the online documentation for the codes.

2.4) Sample Input Files
-----------------------

The "Sample-Input-Files" subfolder contains example VASP input files (INCAR and KPOINTS) for the various types of calculation performed in this study, viz. variable-cell geometry optimisations ("Opt"), constant-volume optimisations for generating the equation of state curves ("EoS"), calculation of the elastic-constant matrices using finite differences ("ElasticConstants"), single-point force calculations for Phonopy ("Phonopy") and calculation of the Born effective charges using density-functional perturbation theory ("BornCharges").
The format and content of these files is fully described in the VASP Wiki.[1]

We note that the projector augmented-wave (PAW) pseudopotentials (POTCAR files) required to perform VASP calculations are distributed under license with the source code and cannot be made available as part of this archive.
Users wishing to reproduce our results will therefore need to rebuild the POTCAR files using the Si and O potentials from the "potpaw_PBE.54" database distributed with VASP 5.4.4.

2.5) References
---------------

1. https://cms.mpi.univie.ac.at/wiki/index.php/The_VASP_Manual (accessed 23/01/2019)
2. http://jp-minerals.org/vesta/en/ (accessed 23/01/2019)
3. https://atztogo.github.io/phonopy/ (accessed 23/01/2019)
4. https://github.com/JMSkelton/Phonopy-Spectroscopy (accessed 23/01/2019)
