Single-crystal neutron Laue diffraction dataset for L-alanine at 100 K

This submission contains the results of crystal structure refinement against experimental single-crystal neutron Laue data for L-alanine crystal collected at 100K. The results were used to validate multipole model refinement from experimental high-resolution single-crystal three-dimensional electron diffraction data (3DED) for L-alanine data set deposited here: https://doi.org/10.18150/VNLTKK. The dataset includes:Raw experimental data collected at 100K and data reduction results (LAla_2026_02_02_100K.zip)Final CIF file documenting the whole process (L-Ala_CIF.zip)Crystals of L-alanine for the neutron diffraction experiment were grown by slow evaporation of water.The neutron diffraction experiments were performed at the OPAL Research Reactor of the Australian Nuclear Science and Technology Organization using the single-crystal Laue diffractometer (KOALA2 )[Edwards, A. J. Neutron Diffraction-Recent Applications to Chemical Structure Determination Aust. J. Chem. 2011, 64, 869– 872 DOI: 10.1071/CH11234], in its latest iteration KOALA2, stands at the end guide position of thermal neutron guide TG3 and utilizes the full wavelength range available therein. The lower wavelength cutoff varies for the different compounds according to the resolving power of the crystal. Single crystal of L-alanine was accordingly affixed on an aluminum hook with a small amount of Paratone-N oil. The crystal was in all instances flash-cooled on mounting to the φ axis of the Laue diffractometer into the nitrogen stream from an Oxford Cryosystems COBRA™ cryostream preset to a prescribed temperature. Laue patterns were recorded from the stationary crystal with a large cylindrical imaging plate detector. For L-alanine, a set of 11 diffraction images separated by sequential φ rotations of 17° has been collected from a single orientation of crystal specimen of 1.4x1.1 x 1.0mm with exposure times of 6700s / image. Indexing, integration, normalization, and data reduction were performed via the program LaueG, [Piltz, R. O. Accurate data processing for neutron Laue diffractometers. J. Appl. Crystallogr. 2018, 51, 635– 645, DOI: 10.1107/S1600576718005058, Piltz, R. O. LaueG software for displaying and processing neutron Laue images J. Appl. Crystallogr. 2018, 51, 963-965, DOI: 10.1107/S1600576718005046] with the integration being based on the Argonne boxes procedure [Wilkinson, C.; Khamis, H. W.; Stansfield, R.; McIntyre, G. Integration of single-crystal reflections using area multidetectors J. Appl. Crystallogr. 1988, 21, 471– 478 DOI: 10.1107/S0021889888005400].Crystal structures were refined using SHELXL 2019/3 [Sheldrick, G. M. SHELXT - integrated space-group and crystal-structure determination. Acta Crystallogr. A 2015, 71, 3–8. DOI: 10.1107/S2053273314026370] in Olex2 1.5-alpha [Dolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. OLEX2 : a complete structure solution, refinement and analysis program. J. Appl. Crystallogr. 2009, 42, 339–341. DOI: 10.1107/S0021889808042726] without restraints, with H-atoms located directly from the difference Fourier map and their atomic displacement parameters (ADPs) refined anisotropically in harmonic approximation. No extinction correction was required.