{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,13]],"date-time":"2025-11-13T02:10:19Z","timestamp":1762999819765,"version":"build-2065373602"},"reference-count":50,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2023,5,12]],"date-time":"2023-05-12T00:00:00Z","timestamp":1683849600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia through FEDER (European Fund for Regional Development)-COMPETE-QREN-EU","award":["UID\/FIS\/04650\/2013","UID\/FIS\/04650\/2019","PTDC\/NAN-MAT\/0098\/2020","UIDB\/50006\/2020","UIDP\/50006\/2020","LA\/P\/0008\/2020","UIDB\/04378\/2020","UIDP\/04378\/2020","LA\/P\/0140\/2020"],"award-info":[{"award-number":["UID\/FIS\/04650\/2013","UID\/FIS\/04650\/2019","PTDC\/NAN-MAT\/0098\/2020","UIDB\/50006\/2020","UIDP\/50006\/2020","LA\/P\/0008\/2020","UIDB\/04378\/2020","UIDP\/04378\/2020","LA\/P\/0140\/2020"]}]},{"name":"E-Field\u2014\u201cElectric-Field Engineered Lattice Distortions (E-FiELD) for optoelectronic devices\u201d","award":["UID\/FIS\/04650\/2013","UID\/FIS\/04650\/2019","PTDC\/NAN-MAT\/0098\/2020","UIDB\/50006\/2020","UIDP\/50006\/2020","LA\/P\/0008\/2020","UIDB\/04378\/2020","UIDP\/04378\/2020","LA\/P\/0140\/2020"],"award-info":[{"award-number":["UID\/FIS\/04650\/2013","UID\/FIS\/04650\/2019","PTDC\/NAN-MAT\/0098\/2020","UIDB\/50006\/2020","UIDP\/50006\/2020","LA\/P\/0008\/2020","UIDB\/04378\/2020","UIDP\/04378\/2020","LA\/P\/0140\/2020"]}]},{"name":"Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia FCT\/MCTES","award":["UID\/FIS\/04650\/2013","UID\/FIS\/04650\/2019","PTDC\/NAN-MAT\/0098\/2020","UIDB\/50006\/2020","UIDP\/50006\/2020","LA\/P\/0008\/2020","UIDB\/04378\/2020","UIDP\/04378\/2020","LA\/P\/0140\/2020"],"award-info":[{"award-number":["UID\/FIS\/04650\/2013","UID\/FIS\/04650\/2019","PTDC\/NAN-MAT\/0098\/2020","UIDB\/50006\/2020","UIDP\/50006\/2020","LA\/P\/0008\/2020","UIDB\/04378\/2020","UIDP\/04378\/2020","LA\/P\/0140\/2020"]}]},{"name":"Associate Laboratory for Green Chemistry\u2014LAQV","award":["UID\/FIS\/04650\/2013","UID\/FIS\/04650\/2019","PTDC\/NAN-MAT\/0098\/2020","UIDB\/50006\/2020","UIDP\/50006\/2020","LA\/P\/0008\/2020","UIDB\/04378\/2020","UIDP\/04378\/2020","LA\/P\/0140\/2020"],"award-info":[{"award-number":["UID\/FIS\/04650\/2013","UID\/FIS\/04650\/2019","PTDC\/NAN-MAT\/0098\/2020","UIDB\/50006\/2020","UIDP\/50006\/2020","LA\/P\/0008\/2020","UIDB\/04378\/2020","UIDP\/04378\/2020","LA\/P\/0140\/2020"]}]},{"name":"UCIBIO and Associate Laboratory i4HB","award":["UID\/FIS\/04650\/2013","UID\/FIS\/04650\/2019","PTDC\/NAN-MAT\/0098\/2020","UIDB\/50006\/2020","UIDP\/50006\/2020","LA\/P\/0008\/2020","UIDB\/04378\/2020","UIDP\/04378\/2020","LA\/P\/0140\/2020"],"award-info":[{"award-number":["UID\/FIS\/04650\/2013","UID\/FIS\/04650\/2019","PTDC\/NAN-MAT\/0098\/2020","UIDB\/50006\/2020","UIDP\/50006\/2020","LA\/P\/0008\/2020","UIDB\/04378\/2020","UIDP\/04378\/2020","LA\/P\/0140\/2020"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>A polymorph of glycyl-L-alanine HI.H2O is synthesized from chiral cyclo-glycyl-L-alanine dipeptide. The dipeptide is known to show molecular flexibility in different environments, which leads to polymorphism. The crystal structure of the glycyl-L-alanine HI.H2O polymorph is determined at room temperature and indicates that the space group is polar (P21), with two molecules per unit cell and unit cell parameters a = 7.747 \u00c5, b = 6.435 \u00c5, c = 10.941 \u00c5, \u03b1 = 90\u00b0, \u03b2 = 107.53(3)\u00b0, \u03b3 = 90\u00b0 and V = 520.1(7) \u00c53. Crystallization in the polar point group 2, with one polar axis parallel to the b axis, allows pyroelectricity and optical second harmonic generation. Thermal melting of the glycyl-L-alanine HI.H2O polymorph starts at 533 K, close to the melting temperature reported for cyclo-glycyl-L-alanine (531 K) and 32 K lower than that reported for linear glycyl-L-alanine dipeptide (563 K), suggesting that although the dipeptide, when crystallized in the polymorphic form, is not anymore in its cyclic form, it keeps a memory of its initial closed chain and therefore shows a thermal memory effect. Here, we report a pyroelectric coefficient as high as 45 \u00b5C\/m2K occurring at 345 K, one order of magnitude smaller than that of semi-organic ferroelectric triglycine sulphate (TGS) crystal. Moreover, the glycyl-L-alanine HI.H2O polymorph displays a nonlinear optical effective coefficient of 0.14 pm\/V, around 14 times smaller than the value from a phase-matched inorganic barium borate (BBO) single crystal. The new polymorph displays an effective piezoelectric coefficient equal to deff=280\u00a0pCN\u22121, when embedded into electrospun polymer fibers, indicating its suitability as an active system for energy harvesting.<\/jats:p>","DOI":"10.3390\/ma16103690","type":"journal-article","created":{"date-parts":[[2023,5,12]],"date-time":"2023-05-12T09:26:13Z","timestamp":1683883573000},"page":"3690","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["A Polymorph of Dipeptide Halide Glycyl-L-Alanine Hydroiodide Monohydrate: Crystal Structure, Optical Second Harmonic Generation, Piezoelectricity and Pyroelectricity"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5380-9212","authenticated-orcid":false,"given":"Rosa M. F.","family":"Baptista","sequence":"first","affiliation":[{"name":"Centre of Physics of Minho and Porto Universities (CF-UM-UP), Laboratory for Materials and Emergent Technologies (LAPMET), University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3672-0045","authenticated-orcid":false,"given":"Clara S. B.","family":"Gomes","sequence":"additional","affiliation":[{"name":"LAQV-REQUIMTE, Department of Chemistry, NOVA School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, Portugal"},{"name":"UCIBIO, Department of Chemistry, NOVA School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, Portugal"},{"name":"i4HB, NOVA School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8408-8235","authenticated-orcid":false,"given":"Bruna","family":"Silva","sequence":"additional","affiliation":[{"name":"Centre of Physics of Minho and Porto Universities (CF-UM-UP), Laboratory for Materials and Emergent Technologies (LAPMET), University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7538-6847","authenticated-orcid":false,"given":"Jo\u00e3o","family":"Oliveira","sequence":"additional","affiliation":[{"name":"Centre of Physics of Minho and Porto Universities (CF-UM-UP), Laboratory for Materials and Emergent Technologies (LAPMET), University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal"}]},{"given":"Bernardo","family":"Almeida","sequence":"additional","affiliation":[{"name":"Centre of Physics of Minho and Porto Universities (CF-UM-UP), Laboratory for Materials and Emergent Technologies (LAPMET), University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0732-1774","authenticated-orcid":false,"given":"Cid\u00e1lia","family":"Castro","sequence":"additional","affiliation":[{"name":"Institute for Polymers and Composites, University of Minho, Campus de Azur\u00e9m, 4800-058 Guimar\u00e3es, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0397-8808","authenticated-orcid":false,"given":"Pedro V.","family":"Rodrigues","sequence":"additional","affiliation":[{"name":"Institute for Polymers and Composites, University of Minho, Campus de Azur\u00e9m, 4800-058 Guimar\u00e3es, Portugal"}]},{"given":"Ana","family":"Machado","sequence":"additional","affiliation":[{"name":"Institute for Polymers and Composites, University of Minho, Campus de Azur\u00e9m, 4800-058 Guimar\u00e3es, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9725-2623","authenticated-orcid":false,"given":"Ruben B.","family":"Freitas","sequence":"additional","affiliation":[{"name":"Department of Electronic Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal"}]},{"given":"Manuel J. L. F.","family":"Rodrigues","sequence":"additional","affiliation":[{"name":"Centre of Physics of Minho and Porto Universities (CF-UM-UP), Laboratory for Materials and Emergent Technologies (LAPMET), University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal"}]},{"given":"Etelvina","family":"de Matos Gomes","sequence":"additional","affiliation":[{"name":"Centre of Physics of Minho and Porto Universities (CF-UM-UP), Laboratory for Materials and Emergent Technologies (LAPMET), University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7968-5038","authenticated-orcid":false,"given":"Michael","family":"Belsley","sequence":"additional","affiliation":[{"name":"Centre of Physics of Minho and Porto Universities (CF-UM-UP), Laboratory for Materials and Emergent Technologies (LAPMET), University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2023,5,12]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"659","DOI":"10.1515\/zna-1989-0710","article-title":"79,81Br\u2212127I\u2212NQR, and Crystal Structure of Glycyl-l-alanine Hydrobromide Monohydrate and Hydroiodide Monohydrate","volume":"44","author":"Kehrer","year":"1989","journal-title":"Z. Naturforsch. A"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"405","DOI":"10.1080\/00150199008214617","article-title":"The pyroelectric coefficient of glycyl-l-alanine hydrobromide monohydrate and glycyl-alanine hydrolodide monohydrate","volume":"106","author":"Kehrer","year":"1990","journal-title":"Ferroelectrics"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"221","DOI":"10.1038\/173221a0","article-title":"Crystal Structure of Glycyl-L-Alanine Hydrobromide","volume":"173","author":"Tranter","year":"1954","journal-title":"Nature"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"37","DOI":"10.1038\/177037a0","article-title":"Crystal Structure of Glycyl-L-Alanine Hydrochloride","volume":"177","author":"Tranter","year":"1956","journal-title":"Nature"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"151","DOI":"10.1016\/0196-9781(94)00017-Z","article-title":"Bioactive cyclic dipeptides","volume":"16","author":"Prasad","year":"1995","journal-title":"Peptides"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1478","DOI":"10.1002\/jrs.2293","article-title":"Vibrational spectroscopy and DFT calculations of di-amino acid cyclic peptides. Part I: Cyclo(Gly-Gly), cyclo(L-Ala-L-Ala) and cyclo(L-Ala-Gly) in the solid state and in aqueous solution","volume":"40","author":"Mendham","year":"2009","journal-title":"J. Raman Spectrosc."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1053","DOI":"10.1126\/science.1190672","article-title":"An Adaptable Peptide-Based Porous Material","volume":"329","author":"Rabone","year":"2010","journal-title":"Science"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"119","DOI":"10.1023\/A:1010114012269","article-title":"Correlation Between Phase Transition Thermodynamics and Crystal Features of Solid Small Peptides","volume":"57","author":"Barone","year":"1999","journal-title":"J. Therm. Anal. Calorim."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"361","DOI":"10.1107\/S2052252514014845","article-title":"Hirshfeld atom refinement","volume":"1","author":"Capelli","year":"2014","journal-title":"IUCrJ"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2269","DOI":"10.1002\/anie.200250684","article-title":"A Conformational Flexibility Scale for Amino Acids in Peptides","volume":"42","author":"Huang","year":"2003","journal-title":"Angew. Chem. Int. Ed."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"105","DOI":"10.1007\/BF02328933","article-title":"A comprehensive optical second harmonic generation study of the non-centrosymmetric character of biological structures","volume":"6","author":"Delfino","year":"1978","journal-title":"J. Biol. Phys."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"3330","DOI":"10.1016\/S0006-3495(02)75673-7","article-title":"Polarization-Modulated Second Harmonic Generation in Collagen","volume":"82","author":"Stoller","year":"2002","journal-title":"Biophys. J."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"637","DOI":"10.1002\/ijch.201400164","article-title":"Symmetry of Bioinspired Short Peptide Nanostructures and Their Basic Physical Properties","volume":"55","author":"Handelman","year":"2015","journal-title":"Isr. J. Chem."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1016\/j.nanoen.2014.11.059","article-title":"Piezoelectric nanogenerators\u2014A review of nanostructured piezoelectric energy harvesters","volume":"14","author":"Briscoe","year":"2015","journal-title":"Nano Energy"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1929","DOI":"10.1134\/1.1514783","article-title":"Piezoelectric properties of crystals of some protein aminoacids and their related compounds","volume":"44","author":"Lemanov","year":"2002","journal-title":"Phys. Solid State"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"207","DOI":"10.1080\/00150190390206040","article-title":"Protein Amino Acid Crystals: Structure, Symmetry, Physical Properties","volume":"285","author":"Lemanov","year":"2003","journal-title":"Ferroelectrics"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"045049","DOI":"10.1088\/2053-1591\/aabd1c","article-title":"Piezoelectric and pyroelectric properties of DL-alanine and L-lysine amino-acid polymer nanofibres","volume":"5","author":"Viseu","year":"2018","journal-title":"Mater. Res. Express"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"13566","DOI":"10.1038\/ncomms13566","article-title":"Self-assembly of diphenylalanine peptide with controlled polarization for power generation","volume":"7","author":"Nguyen","year":"2016","journal-title":"Nat. Commun."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"4339","DOI":"10.1039\/C9NA00464E","article-title":"Self-assembly of dipeptide Boc-diphenylalanine nanotubes inside electrospun polymeric fibers with strong piezoelectric response","volume":"1","author":"Baptista","year":"2019","journal-title":"Nanoscale Adv."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"2934","DOI":"10.1039\/D1MA01022K","article-title":"Self-assembly of Boc-p-nitro-l-phenylalanyl-p-nitro-l-phenylalanine and Boc-l-phenylalanyl-l-tyrosine in solution and into piezoelectric electrospun fibers","volume":"3","author":"Baptista","year":"2022","journal-title":"Mater. Adv."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1016\/j.mattod.2019.04.002","article-title":"Stable and optoelectronic dipeptide assemblies for power harvesting","volume":"30","author":"Tao","year":"2019","journal-title":"Mater. Today"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1807481","DOI":"10.1002\/adma.201807481","article-title":"Bioinspired Stable and Photoluminescent Assemblies for Power Generation","volume":"31","author":"Tao","year":"2019","journal-title":"Adv. Mater."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Santos, D., Baptista, R.M.F., Handa, A., Almeida, B., Rodrigues, P.V., Torres, A.R., Machado, A., Belsley, M., and de Matos Gomes, E. (2023). Bioinspired Cyclic Dipeptide Functionalized Nanofibers for Thermal Sensing and Energy Harvesting. Materials, 16.","DOI":"10.20944\/preprints202302.0365.v1"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"4288","DOI":"10.1021\/cg2009336","article-title":"Production of Polar \u03b2-Glycine Nanofibers with Enhanced Nonlinear Optical and Piezoelectric Properties","volume":"11","author":"Isakov","year":"2011","journal-title":"Cryst. Growth Des."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"610","DOI":"10.1021\/nn901327v","article-title":"Strong Piezoelectricity in Bioinspired Peptide Nanotubes","volume":"4","author":"Kholkin","year":"2010","journal-title":"ACS Nano"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"8138","DOI":"10.1021\/acsnano.8b03118","article-title":"Diphenylalanine Peptide Nanotube Energy Harvesters","volume":"12","author":"Lee","year":"2018","journal-title":"ACS Nano"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1107\/S1600576714022985","article-title":"Comparison of silver and molybdenum microfocus X-ray sources for single-crystal structure determination","volume":"48","author":"Krause","year":"2015","journal-title":"J. Appl. Crystallogr."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1107\/S2053229614024218","article-title":"Crystal structure refinement with SHELXL","volume":"71","author":"Sheldrick","year":"2015","journal-title":"Acta Crystallogr. Sec. C"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"849","DOI":"10.1107\/S0021889812029111","article-title":"WinGX and ORTEP for Windows: An update","volume":"45","author":"Farrugia","year":"2012","journal-title":"J. Appl. Crystallogr."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"226","DOI":"10.1107\/S1600576719014092","article-title":"Mercury 4.0: From visualization to analysis, design and prediction","volume":"53","author":"Macrae","year":"2020","journal-title":"J. Appl. Crystallogr."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1063\/1.2062916","article-title":"Pyroelectricity: From Ancient Curiosity to Modern Imaging Tool","volume":"58","author":"Lang","year":"2005","journal-title":"Phys. Today"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"4978","DOI":"10.1039\/c2nr30771e","article-title":"Strong enhancement of second harmonic generation in 2-methyl-4-nitroaniline nanofibers","volume":"4","author":"Isakov","year":"2012","journal-title":"Nanoscale"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"171","DOI":"10.1107\/S2052520616003954","article-title":"The Cambridge Structural Database","volume":"72","author":"Groom","year":"2016","journal-title":"Acta Crystallogr. Sec. B"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"073505","DOI":"10.1063\/1.2591237","article-title":"Piezoelectric, nonlinear optical, electro-optical, and pyroelectric properties of cesium hydrogen malate hydrate crystal","volume":"90","author":"Isakov","year":"2007","journal-title":"Appl. Phys. Lett."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"1289","DOI":"10.1515\/zna-1986-1104","article-title":"Dielectric and pyroelectric properties of lithium hydrogen dimalate, LiH3(C4H4O5)2","volume":"41","author":"Fleck","year":"1986","journal-title":"Z. Naturforsch. A"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"084004","DOI":"10.1088\/1361-665X\/aac0b3","article-title":"A dynamic method for the measurement of pyroelectric properties of materials","volume":"27","author":"Kroener","year":"2018","journal-title":"Smart. Mater. Struct."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"3839","DOI":"10.1021\/cg5003644","article-title":"Pyroelectricity in Nonpolar Directions in Crystals: Enantiomeric Disorder and Surface Wetting in Racemic \u03b1-Amino-Acids","volume":"14","author":"Mishuk","year":"2014","journal-title":"Cryst. Growth Des."},{"key":"ref_38","unstructured":"Nelson, D.F. (1993). Numerical Data and Functional Relationships in Science and Technology, Springer."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"32722","DOI":"10.1039\/C9RA05730G","article-title":"Melting properties of peptides and their solubility in water. Part 1: Dipeptides based on glycine or alanine","volume":"9","author":"Do","year":"2019","journal-title":"Rsc. Adv."},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Kremer, F., and Sch\u00f6nhals, A. (2002). Broadband Dielectric Spectroscopy, Springer Science & Business Media.","DOI":"10.1007\/978-3-642-56120-7"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"2405","DOI":"10.1007\/s11581-019-03243-7","article-title":"Numerical comparison of usual Arrhenius-type equations for modeling ionic transport in solids","volume":"26","author":"Nuernberg","year":"2020","journal-title":"Ionics"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"560","DOI":"10.1038\/s41578-021-00289-w","article-title":"Polarons in materials","volume":"6","author":"Franchini","year":"2021","journal-title":"Nat. Rev. Mater."},{"key":"ref_43","unstructured":"Nye, J.F. (1985). Physical Properties of Crystals: Their Representation by Tensors and Matrices, Oxford University Press."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"306","DOI":"10.1126\/science.aai8535","article-title":"An organic-inorganic perovskite ferroelectric with large piezoelectric response","volume":"357","author":"You","year":"2017","journal-title":"Science"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"44","DOI":"10.1039\/D0QM00288G","article-title":"Recent progress in the piezoelectricity of molecular ferroelectrics","volume":"5","author":"Pan","year":"2021","journal-title":"Mater. Chem. Front."},{"key":"ref_46","doi-asserted-by":"crossref","unstructured":"Baptista, R.M.F., Moreira, G., Silva, B., Oliveira, J., Almeida, B., Castro, C., Rodrigues, P.V., Machado, A., Belsley, M., and de Matos Gomes, E. (2022). Lead-Free MDABCO-NH4I3 Perovskite Crystals Embedded in Electrospun Nanofibers. Materials, 15.","DOI":"10.3390\/ma15238397"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"2201","DOI":"10.1080\/00268970903224955","article-title":"First principles determination of structural, electronic and lattice dynamical properties of a model dipeptide molecular crystal","volume":"107","author":"Tulip","year":"2009","journal-title":"Mol. Phys."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"6971","DOI":"10.1364\/AO.44.006971","article-title":"Effective second-order nonlinearity in acentric optical crystals with low symmetry","volume":"44","author":"Tzankov","year":"2005","journal-title":"Appl. Opt."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"1600","DOI":"10.1109\/JQE.2003.819531","article-title":"Efficiency of short-pulse type-I second-harmonic generation with simultaneous spatial walk-off, temporal walk-off, and pump depletion","volume":"39","author":"Wang","year":"2003","journal-title":"IEEE J. Quantum Elect."},{"key":"ref_50","unstructured":"D\u2019Errico, J. (2022, March 07). Fminspleas Available at MATLAB Central File Exchange. Available online: https:\/\/www.mathworks.com\/matlabcentral\/fileexchange\/10093-fminspleas."}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/16\/10\/3690\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T19:33:34Z","timestamp":1760124814000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/16\/10\/3690"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,5,12]]},"references-count":50,"journal-issue":{"issue":"10","published-online":{"date-parts":[[2023,5]]}},"alternative-id":["ma16103690"],"URL":"https:\/\/doi.org\/10.3390\/ma16103690","relation":{},"ISSN":["1996-1944"],"issn-type":[{"type":"electronic","value":"1996-1944"}],"subject":[],"published":{"date-parts":[[2023,5,12]]}}}