# Na2SO42/DFT_Calculations/CASTEP/
Summary description of directory structure for calculations using CASTEP
##Cutoff/
Contains the results of the calculations used to determine the energy cutoffs
Each results directory contains a directory labelled with the energy cutoff used for the calculation stored.
The cutoff energy units are in electron volts.
##FineGridScale/
The fine_grid_scale parameter was optimised by determining the acoustic mode frequencies at the experimental unit cell dimensions.
- **fine3/** fine_grid_scale = 3
- **fine4/** fine_grid_scale = 4
- **fine5/** fine_grid_scale = 5
- **fine6/** fine_grid_scale = 6
##Phonons/
Contains the result directories of the cell optimisation and subsequent calculation of the phonon spectrum.
###Phonons/NoDispersion
Contains the directories for the results with no dispersion
- **Exptl-cell/** Results of a phonon calculation at the experimental unit cell dimensions
- **Optimised-cell/** Results of a phonon calculation at the optimised unit cell dimensions
###Phonons/GD3
Contains the directories for the G06 correction results
####Phonons/GD3/S6_parameter_optimisation
The S6 parameter of the Grimme dispersion correction (G06) was varied to determine a value which gave the best volume or the best root mean deviation from experiment.
- **S6030/** S6 = 0.30
- **S6040/** S6 = 0.40
- **S6050/** S6 = 0.50
- **S6060/** S6 = 0.60
- **S6075/** S6 = 0.75
- **S6090/** S6 = 0.90
- **S6100/** S6 = 0.10
- **S6110/** S6 = 0.11
- **S6120/** S6 = 0.12
- **S6122/** S6 = 0.122
- **S6124/** S6 = 0.124
- **S6140/** S6 = 0.14
- **S6200/** S6 = 0.20
- **S6300/** S6 = 0.30
- **Cifs/** Structures calculated using the different S6 values, written as cif files
###Phonons/TS
Contains directories with results using the TS dispersion correction
####Phonons/TS/SR_parameter_optimisation
The SR parameter of the TS dispersion correction (G06) was varied to determine a value which gave the best volume or the best root mean deviation from experiment.
- **Default/** SR = Default value
- **SR015/** SR = 0.15
- **SR025/** SR = 0.25
- **SR035/** SR = 0.35
- **SR045/** SR = 0.45
- **SR055/** SR = 0.55
- **SR065/** SR = 0.65
- **SR075/** SR = 0.75
- **SR085/** SR = 0.85
- **SR0905/** SR = 0.905
- **SR0910/** SR = 0.910
- **SR0916/** SR = 0.916
- **SR110/** SR = 0.110
####Phonons/TS/Default_Sr
Phonon calculation using the default TS parameters with the optimised cell
####Phonons/TS/Optimised_SR
Phonon calculation using the optimised SR parameter TS with the optimised cell
## Description of files in the results directories
In each results directory there are the following files;
### Pseudo-potential files
The pseudo-potential files were generated on the flying using the NCP17 directive
- O_NCP17_PBE_OTF.usp
- S_NCP17_PBE_OTF.usp
- Na_NCP17_PBE_OTF.usp
### Input files for geometry optimisation
- Na2SO42.cell
- Na2SO42.param
### Output files for geometry optimisation
- Na2SO42.castep
- Na2SO42.geom
- Na2SO42.log
### Input files for phonon calculation
- Na2SO42.cell
- Na2SO42.param
### Output files for phonon calculation
- Na2SO42_phonon.castep
- Na2SO42_phonon.geom
- Na2SO42_phonon.bands
- Na2SO42_phonon.bib
- Na2SO42_phonon.efield
- Na2SO42_phonon.phonon
- Na2SO42_phonon.log