This repository contains key raw data from the manuscript:

Sulfamerazine: Understanding the Influence of Slip Planes in the Polymorphic Phase Transformation through X‐Ray Crystallographic Studies and ab Initio Lattice Dynamics
Anuradha R. Pallipurath, Jonathan M. Skelton, Mark R. Warren, Naghmeh Kamali, Patrick McArdle, and Andrea Erxleben
Molecular Pharmaceutics (2015)
DOI: 10.1021/acs.molpharmaceut.5b00504

General:

This repository contains a subset of the raw data discussed in the above manuscript, in particular the single-crystal X-ray structures of Sulfamerazine Forms I and II from the temperature-dependent diffraction studies, the optimised structures from the computational modelling, and the raw data from the lattice-dynamics calculations. Any data not available from this repository may be requested from the authors.

Available data:

The data is organised into five subfolders. The experimental data on Forms I and II is bundled into folders named “Exp_Form-[I / II]”, while data from the computational modelling on Forms I, II and III is stored in folders named “Calc_Form-[I / II / III]”.

For details of the experimental and computational methodology, please refer to the manuscript.

The archive contains the following data:

1.	 Single-crystal X-ray structures of Forms I and II from the temperature-dependent diffraction studies.

These are named according to the following convention:

[InHouse / Synchrotron]_Form-[I / II]_[MeasurementTemperature].cif

The first part of the file name labels whether the data was recorded on the in-house instrument, or at the Diamond Light Source synchrotron facility. The second part indicates whether the structure is of Form I or Form II. The last part gives the temperature at which the measurements were performed.

Each structure is given as a single Crystallographic Information Format (CIF) file, which can be viewed with e.g. the Mercury (http://www.ccdc.cam.ac.uk/Solutions/FreeSoftware/Pages/FreeMercury.aspx, last checked 07/09/2015) or VESTA (http://jp-minerals.org/vesta/en/, last checked 02/09/2015) software.

2.	Optimised structures of Forms I, II and III obtained from the computational modelling. 

There are three sets of structures for each polymorph.

The first are the optimised structures used in the lattice-dynamics calculations, which are named:

Form-[I / II / III]_[PBE / PBEsol / PBE-D2]_[Relaxed / ModeFollow-Relaxed].vasp

The first part of the file name indicates the phase of Sulfamerazine (Form I/II/III). The second part gives the density-functional theory (DFT) functional used for the optimisation. The last part indicates how the structure was optimised, and is one of:
a)	“Relaxed” - the atom positions were optimised starting from the experimental crystal structure, with the lattice parameters kept fixed.
b)	“ModeFollow-Relaxed” - the atom positions were re-optimised after following the imaginary phonon modes in the relaxed structures (from a).

The second set of structures are the models optimised during the construction of the equation-of-state (EoS; E/V) curves. These files are named:

Form-[I / II / III]_PBE-D2_V-[Volume].vasp

As above, the first part of the file name denotes the polymorph of Sulfamerazine, while the last gives the (fixed) cell volume at which the atomic positions and cell shape were optimised.

For convenience, the EoS structures are bundled into TAR archives compressed with the GZip algorithm, which are named:

Form-[I / II / III]_PBE-D2_EoS.tar.gz

These archives can be unpacked with the “tar” utility on Mac OS and Linux, or e.g. the free PeaZip software on Windows (http://www.peazip.org/, last checked 07/09/2015).

Finally, the third set of structures are those for which the cell shape and atomic positions were optimised at the equilibrium volumes determined from the equation-of-state fitting using the VASP code. These are the structures on which the elastic-property calculations were carried out. They are named:

Form-[I / II / III]_PBE-D2_Veq-Relaxed.vasp

All simulated structures are in the VASP POSCAR format (http://cms.mpi.univie.ac.at/vasp/guide/node59.html, last checked 02/09/2015), and can be viewed using e.g. VESTA (http://jp-minerals.org/vesta/en/, last checked 02/09/2015).

3.	Raw data from the lattice-dynamics calculations.

This data is provided as a set of TAR archives compressed with the GZip algorithm. The archives are named as follows:

Form-[I / II / III]_[PBE / PBEsol / PBE-D2]_[Relaxed / ModeFollow-Relaxed].vasp

The file name indicates which of the relaxed structures the phonon calculations were performed on, as outlined in #2 above.

The lattice-dynamics calculations were performed with the Phonopy software (http://phonopy.sourceforge.net/, last checked 07/09/2015), and each archive contains the key files needed to re-run the post processing to generate the results in the manuscript. This includes the structure the calculation was performed on (“POSCAR.vasp”, in the VASP POSCAR format as for the optimised structures), together with the disp.yaml and FORCE_SETS files. These POSCAR files are duplicates of the optimised structures held outside the TAR bundle, and are included in the bundle for convenience.

The archives also include the calculated phonon densities of states and thermodynamic properties, in their raw form and as plots in PDF format. Two versions of each are provided, one computed at the Gamma point (suffixed “1x1x1”), and the other computed using a Gamma-centred Monkhorst-Pack mesh with 32x32x32 subdivisions to integrate the Brillouin zone (suffixed “32x32x32”).