This README_Zachariou_Methyl-torsion_dataset.txt file was generated on 25th November 2019 by Prof. Stewart F. Parker. ------------------- GENERAL INFORMATION ------------------- Title of Dataset: Zachariou_Methyl-torsion Author Information (Name, Institution, Address, Email) Principal Investigator: Prof Stewart F. Parker, ISIS Neutron and Muon Source, STFC Rutherford Appleton Laboratory, Chilton, Oxon, OX11 0QX, UK, stewart.parker@stfc.ac.uk Co-investigators: Ms Andrea Zachariou, Mr Alexander P. Hawkins and Prof David Lennon, School of Chemistry, University of Glasgow, Joseph Black Building, Glasgow G12 8QQ, UK Prof Russell F. Howe, Department of Chemistry, University of Aberdeen, Aberdeen, AB24 3UE, UK Dr Paul Collier, Johnson Matthey Technology Centre, Blounts Court, Sonning Common, Reading, RG4 9NH, UK Date of data collection: 12-17th May 2018 Geographic location of data collection: ISIS Neutron and Muon Source, STFC Rutherford Appleton Laboratory, Chilton, Oxon, OX11 0QX, UK Information about funding sources or sponsorship that supported the collection of the data: STFC Rutherford Appleton Laboratory is thanked for funding and access to neutron beam facilities. Computing resources (time on the SCARF compute cluster for the CASTEP calculations) was provided by STFC's e-Science facility. Dr John Tomkinson (ISIS) is thanked for generously providing the INS spectra of the toluene isotopomers. Johnson Matthey plc. for financial support through the provision of industrial CASE studentships in partnership with the EPSRC. UK Catalysis Hub via membership of the UK Catalysis Hub Consortium and funded by EPSRC grant: EP/R026939/1, EP/R026815/1, EP/R026645/1, EP/R027129/1 or EP/M013219/1(biocatalysis)). -------------------------- SHARING/ACCESS INFORMATION -------------------------- This dataset is licensed by the rights-holder(s) under a Creative Commons Attribution 4.0 International Licence (CC-BY): https://creativecommons.org/licenses/by/4.0/. Recommended citation for the data: Zachariou et al. 2018. Zachariou_Methyl-torsion [Dataset] eData: the STFC Research Data Repository (https://edata.stfc.ac.uk/ ). DOI (this can be obtained from the ‘view item’ page, under ‘URI.’). Citation for and links to publications that cite or use the data: Zachariou et al, ACS Omega (2019). Links to other publicly accessible locations of the data: doi: 10.5286/ISIS.E.RB1810859 (2018). Related data sets: INS database of analysed spectra: http://wwwisis2.isis.rl.ac.uk/INSdatabase/ -------------------- DATA & FILE OVERVIEW -------------------- The dataset consists of four directories compressed as .zip files: "A-Experimental_INS_spectra.zip", "B-CASTEP.zip", "C-Gaussian.zip" "D-Calculated_INS_spectra.zip". "A-Experimental_INS_spectra.zip" contains the INS spectra measured on TOSCA at ISIS as ASCII files (.dat extension) that can be viewed with any text reader or can be loaded into programs such as Excel or Origin to display the spectra. The filename is the name of the compound and the data consists of three columns of ASCII data. Column 1 is the energy transfer in wavenumber (cm-1), column 2 is the intensity S(Q,w) (arbitrary units) and column three is the error bar of the intensity given in column 2. There are three spectra listed sequentially in each file and separated by 0,1,2. The first "0" are the data from the backscattering detectors, "1" are the data from the forward scattering detectors and "2" is the arithmetic average of the forward and back scattering detectors. This is the spectrum that is normally displayed and is that shown in the ACSOmega paper and on the INS database. "B-CASTEP.zip" contains the output from the CASTEP program. Each compound studied has its own directory, with the name of the compound. Note that only compounds for which the crystal structure is known are present here. In each directory is one or more directories that ends in "CASTEP GeomOpt". Each of these contains the CASTEP input files (.cell and .param) and the output file (.castep). The output file includes the geometry optimised structure. There is also a directory whose name ends in "CASTEP Properties" that contains the CASTEP input files (.cell and .param) and the output files (.castep and .phonon) for the vibrational calculation. The .phonon file includes both the transition energies and atomic displacements for all the atoms in each mode. If the filename contains "_Efield" then it is a gamma-point only calculation (hence only contains one set of frequencies), if it contains "_PhonDisp" then it is a complete Brillouin zone calculation at multiple points in the Brillouin zone (hence contains one multiple sets of frequencies), to include the effects of vibrational dispersion. Some of the directories only have one "CASTEP GeomOpt" present, some where there several calculations have more than one. In particular, the "Mesitylene" and "Hexamethylbenzene" directories contain files of the form "Compound_iso_XXA CASTEP GeomOpt". These are for a single molecule in a cubic box whose side is XX Angstrom in length. "C-Gaussian.zip" contains the input (.gjf) and output files (.out) for the Gaussian calculations. "D-Calculated_INS_spectra.zip" contains comma separated variable (.csv) files of the calculated INS spectra generated from the ab initio (CASTEP and Gaussian) calculations. These can be read by any text reader and loaded directly into Excel or Origin to display the spectra. In all cases, the first column is the energy transfer value, the second column has the intensities for the 0-to-1 transitions, the third for the 0-to-2 transitions and so on. The tenth column (labelled "Total") has the total intensity of all the transitions and is usually the one that is displayed. -------------------------- METHODOLOGICAL INFORMATION -------------------------- The experimental spectra were all measured on TOSCA at ISIS at ~20K. They were converted from time-of-flight to energy transfer using Mantid (version 4.1.0, with the rebin string "3,-0.005,500", available from: https://www.mantidproject.org/Main_Page ). The ab initio data were calculated with Gaussian 09W (version 9.5, using the B3LYP functional and the 6-311g(d) basis set) and CASTEP (version 17.21, using the PBE functional and norm conserving pseudopotentials, full details are included in the .castep output files). INS spectra were generated from the ab initio results (the .out file for Gaussian and the .phonon file for CASTEP) using either the programs ACLIMAX or AbINS (available within Mantid).