DOI: 10.5061/dryad.44j0zpcr2
title: Data for: Stereoregular radical polymers enable selective spin transfer - computational studies (Data S1 and S2) and crystal structure of M1

description: Spintronics offers a promising avenue for surpassing the performance and
 energy efficiency limits of conventional electronic devices. However,
 existing spintronic materials, including metals and doped conjugated
 polymers, face intrinsic stability and performance challenges. To address
 these limitations, we employed computational methods to investigate the
 electronic structure, spin transport properties, and crystallographic
 order of a stereoregular radical polymer. Computational simulations in
 different stereoregularities were utilized to model spin-spin
 interactions, charge delocalization, and long-range order within the
 polymer backbone. Crystallographic data analysis provided insights into
 the molecular packing of the monomer (M1) and the role of stereochemistry
 in controlling spin alignment. Our findings highlight how stereoselective
 polymerization enables persistent radicals in each repeat unit to support
 long-range spin transport without conventional doping. This
 computationally guided approach underscores the potential of stereoregular
 radical polymers as a novel platform for next-generation spintronic
 devices and quantum information processing. The computational
 results support the hypothesis that molecular-level alterations in polymer
 stereochemistry are critical for controlling spin-spin interactions and
 alignment. An additional file containing the crystal data, pre-reported
 and uploaded to CCDC (Cambridge Crystallographic Data Centre) is attached
 - composed by Cole C. Sorensen under the supervision of Frank A.
 Leibfarth. The original works of Data S1 and S2 were composed by Andrew
 Marquardt under the supervision of Brett M. Savoie.
description: Three trimers were analyzed using the Conformer-Rotamer Ensemble
 Sampling Tool (CREST) and GFN2-xTB semi-empirical potential. The trimers
 corresponded to the heterotactic (m,r), syndiotactic (r,r), and isotactic
 (m,m) triads that map to the atactic, syndiotactic, and atactic
 polymerization scenarios. The universal force field (UFF) in the OpenBabel
 quantum chemistry file conversion package was used to generate an initial
 optimized geometry from stereochemically-specific SMILES strings for each
 triad<em>,</em> which was then optimized using xTB before
 being subjected to conformational sampling via CREST using the most
 comprehensive default setting. The initial geometries and outputted
 conformers were analyzed to ensure no incorrect bond rearrangements or
 intramolecular radical dimerization had occurred. Separation and alignment
 analysis was performed on all conformations. Each triad has two pairs of
 nearest neighbors (i.e., the first and second radicals, and the second and
 third radicals) whose alignment and separation were parsed and reflected
 in the histograms. Conformer weights within the distributions were
 calculated via Boltzmann probabilities using the relative energy
 calculated by CREST for each conformer. The alignment
 autocorrelation decay was calculated for each tacticity using the
 alignment data from the corresponding triads. A virtual polymerization was
 performed by Boltzmann sampling (i.e., selecting pairs of alignment angles
 based on the energy of the corresponding triad conformer) the triad
 statistics 250,000 times, producing a sequence of 500,000 pendant radical
 alignments. The alignment decay was calculated from these radical
 sequences using each radical as an independent origin and averaging the
 alignment dot products with respect to separation along the sequence. This
 procedure resulted in 499,900 (i.e., 500,000-100) decay curves that were
 averaged over to yield. The persistence length was reported as the
 separation after which the alignment fell to e<sup>-1</sup>. A
 Jupyter notebook illustrating these calculations is distributed with this
 work.
description: # Data for: Stereoregular radical polymers enable selective spin transfer
 - computational studies (Data S1 and S2) and crystal structure of M1
 [https://doi.org/10.5061/dryad.44j0zpcr2](https://doi.org/10.5061/dryad.44j0zpcr2) ## Description of the data and file structure Computational results (Data S1 and S2) and crystal data of M1. 1. .p files are binary files formatted using the pickle module, a built-in Python package. These files are optimized for efficient data storage and can be readily accessed using the pickle module. When loaded, they are automatically interpreted as Python dictionaries, providing a structured and convenient means of storing and retrieving data. 2. **The raw .p files** given correspond to each trimer conformer ensemble tacticity analyzed during the computational section of the results.  They provide the raw data used to determine Boltzmann distributions of radical chain alignment (as defined by the dot product) and radical separation.  Dictionary headings are as follows, with conformer sequentiality conserved across all data sets/lists: **P**: the Boltzmann probability of each conformer as calculated from the distribution partition function, organized by decreasing probability **S(x)(y)**: the separation between the radical COM (what is meant by COM in this context should be defined in the paper text) of pendants (x) and (y), where x and y are integers sequentially given to the pendants in the trimer. **D(x)(y)**: the dot product between vectors (vector definition used consistent atoms, this is defined in the paper text also)  defining the pendants (x) and (y), where x and y are integers sequentially given to the pendants in the trimer. 3. **magnetic_persistence.ipynb** is a python notebook (which can be run in jupyter or other .ipynb software) that calculates the magnetic persistence of a given conformer. It takes the .p files described above as input data and analyzes the dot product distribution to determine the expected segment length (in pendant monomers) within the polymer at which pendants are sufficiently aligned that the segment can be considered to exhibit magnetic effects. 4. **.cif (Crystallographic Information File)** is a standard text-based file format used for storing and exchanging crystallographic data. Same file is uploaded and published in the database entries in **Cambridge Structural Database (CSD) with a CCDC#: 2324183.** ### Files and variables #### File: boltz\_SRR2.p **Description:** Data S1 - 1 #### File: boltz\_SRS2.p **Description:** Data S1 - 2 #### File: boltz\_SSS2.p **Description:** Data S1 - 3 #### File: magnetic\_persistence.ipynb **Description:** Data S2 #### File: 2324183.cif **Description:** Crystal Data of M1 / CCDC#: 2324183 ## Access information Other publicly accessible locations of the data: * [https://github.com/Savoie-Research-Group/papers](https://github.com/Savoie-Research-Group/papers) * [https://www.ccdc.cam.ac.uk/structures/?gad_source=1&gclid=CjwKCAiA2cu9BhBhEiwAft6IxPrphvEACJ89VGXlIjIXRg3I9OeGBD4EO-1psQuDFgADwbNk11gSphoCCQ8QAvD_BwE](https://www.ccdc.cam.ac.uk/structures/?gad_source=1&gclid=CjwKCAiA2cu9BhBhEiwAft6IxPrphvEACJ89VGXlIjIXRg3I9OeGBD4EO-1psQuDFgADwbNk11gSphoCCQ8QAvD_BwE) Data was derived from the following sources: * Conformer-Rotamer Ensemble Sampling Tool (CREST), GFN2-xTB, OpenBabel quantum chemistry file conversion package