Neutron powder diffraction data of butane collected over ramp of 0.02 K/min between 7.39 - 138.70 K

Neutron powder diffraction data collected from a condensed sample of butane (C4H10) with the Wombat high-intensity neutron diffraction instrument located at the OPAL reactor, Sydney, Australia. Data were collected at a wavelength of 2.422 Å. The files ending in .nx.hdf are raw data files conforming to the NeXus standard (see nexusformat.org). The files ending in .xy are two-column ASCII reduced data derived from the corresponding raw data NeXus file, with the columns being angle, intensity and standard uncertainty of that intensity. To obtain the reduced data from the raw data each pixel was multiplied by the corresponding value in the efficiency map contained in file ‘eff_2025_06_12.gumtree.hdf’, after which all pixels at each angle were summed vertically and the final values output. The detector/x_pixel_angular_offset raw data file entry gives the angular boundaries of each detector pixel. These values were used to derive pixel centres, which were then added to sample/azimuthal_angle to give the final angular values found in the reduced data file. The raw data collected over the ramp spans three files, each collected contiguously (WBT0104371.nx.hdf, WBT0104372.nx.hdf and WBT0104373.nx.hdf). Temperature was ramped continuously through the data collection at a rate of 0.2 K/min and binned into 5 minute blocks, such that each output pattern spans 1 K - measured sample temperature of each point can be read from the raw file sample/tc2/sensor/sensorValueA entry. However, the butane signal in these data was too weak to fit, hence to analyse these data 5 sequential patterns were added together to results in the .xy patterns deposited here. Hence the temperature of these patterns spanned 5 K, in the associated publication the mean temperature for each pattern was used.