A family of solids including crystalline phase change materials such as GeTe and Sb2 Te3 , topological insulators like Bi2 Se3, and halide perovskites such as CsPbI3 possesses an unconventional property portfolio that seems incompatible with ionic, metallic, or covalent bonding. Instead, evidence is found for a bonding mechanism characterized by half-filled p-bands and a competition between electron localization and delocalization. Different bonding concepts have recently been suggested based on quantum chemical bonding descriptors which either define the bonds in these solids as electron-deficient (metavalent) or electron-rich (hypervalent). This disagreement raises concerns about the accuracy of quantum-chemical bonding descriptors is showed. Here independent of the approach chosen, electron-deficient bonds govern the materials mentioned above is showed. A detailed analysis of bonding in electron-rich XeF2 and electron-deficient GeTe shows that in both cases p-electrons govern bonding, while s-electrons only play a minor role. Yet, the properties of the electron-deficient crystals are very different from molecular crystals of electron-rich XeF2 or electron-deficient B2 H6 . The unique properties of phase change materials and related solids can be attributed to an extended system of half-filled bonds, providing further arguments as to why a distinct nomenclature such as metavalent bonding is adequate and appropriate for these solids.

1 Institute of Physics Physics of Novel Materials RWTH Aachen University 52056 Aachen Germany

CESAM B5 Université de Liège Sart Tilman Liège B4000 Belgium

CNR SCITEC Istituto di Scienze e Tecnologie Chimiche Giulio Natta sezione di via Golgi via Golgi 19 Milano 20133 Italy

Departamento de Química Física y Analítica Julián Clavería 8 Oviedo 33006 Spain

Department of Theoretical Chemistry J Heyrovský Institute of Physical Chemistry Dolejškova 2155 3 Prague 18223 Czech Republic

Green IT Forschungszentrum Jülich GmbH 52428 Jülich Germany

Jülich Aachen Research Alliance RWTH Aachen University 52056 Aachen Germany

Theoretical Sciences Unit School of Advanced Materials JNCASR Jakkur Bangalore 560064 India

Zernike Institute for Advanced Materials University of Groningen Nijenborgh 4 Groningen 9747AG The Netherlands

Zobrazit více v PubMed

Wuttig M., Schön C. F., Loetfering J., Golub P., Gatti C., Raty J. Y., Adv. Mater. 2023, 35, 2208485. PubMed

Siegrist T., Jost P., Volker H., Woda M., Merkelbach P., Schlockermann C., Wuttig M., Nat. Mater. 2011, 10, 202. PubMed

Wuttig M., Schon C. F., Schumacher M., Robertson J., Golub P., Bousquet E., Gatti C., Raty J. Y., Adv. Funct. Mater. 2021, 32, 2110166.

Lucovsky G., White R. M., Phys. Rev. B 1973, 8, 660.

Pauling L., The Nature of the Chemical Bond, Cornell Univ. Press, New York: 1960.

Shportko K., Kremers S., Woda M., Lencer D., Robertson J., Wuttig M., Nat. Mater. 2008, 7, 653. PubMed

Wuttig M., Deringer V. L., Gonze X., Bichara C., Raty J.‐Y., Adv. Mater. 2018, 30, 1803777. PubMed

Zhu M., Cojocaru‐Mirédin O., Mio A. M., Keutgen J., Küpers M., Yu Y., Cho J.‐Y., Dronskowski R., Wuttig M., Adv. Mater. 2018, 30, 1706735. PubMed

Cheng Y. D., Wahl S., Wuttig M., Phys. Status Solidi‐Rapid Res. Lett. 2021, 15, 2000482.

Raghuwanshi M., Cojocaru‐Mirédin O., Wuttig M., Nano Lett. 2020, 20, 116. PubMed

Raty J.‐Y., Schumacher M., Golub P., Deringer V. L., Gatti C., Wuttig M., Adv. Mater. 2019, 31, 6. PubMed

Jones R. O., Elliott S. R., Dronskowski R., Adv. Mater. 2023, 35, 2300836. PubMed

a) Maier S., Steinberg S., Cheng Y., Schön C.‐F., Schumacher M., Mazzarello R., Golub P., Nelson R., Cojocaru‐Mirédin O., Raty J.‐Y., Wuttig M., Adv. Mater. 2020, 32, 2005533; PubMed

b) Cheng Y., Cojocaru‐Mirédin O., Keutgen J., Yu Y., Küpers M., Schumacher M., Golub P., Raty J.‐Y., Dronskowski R., Wuttig M., Adv. Mater. 2019, 31, 1904316; PubMed

c) Wuttig M., Schön C.‐F., Lötfering J., Golub P., Gatti C., Raty J.‐Y., Adv. Mater. 2022, 35, 2208485. PubMed

Baranov A. I., Kohout M., J. Comput. Chem. 2011, 32, 2064. PubMed

Golub P., Baranov A. I., J. Chem. Phys. 2016, 145, 154107. PubMed

Otero‐De‐La‐Roza A., Johnson E. R., Luaña V., Comput. Phys. Commun. 2014, 185, 1007.

Müller P. C., Ertural C., Hempelmann J., Dronskowski R., J. Phys. Chem. C 2021, 125, 7959.

Wiberg K. B., Tetrahedron 1968, 24, 1083.

Mayer I., Chem. Phys. Lett. 1983, 97, 270.

Mayer I., J. Comput. Chem. 2007, 28, 204. PubMed

Outeiral C., Vincent M. A., Martín Pendás Á., Popelier P. L. A., Chem. Sci. 2018, 9, 5517. PubMed PMC

Bergerem S. V., Schön C.‐F., Mattes C., Yadav A., Grohe M., Kobbelt L., Wuttig M., Sci. Adv. 2023, 8, eade0828. PubMed PMC

Hoffmann R., Angew. Chem.‐Int. Edit. Engl. 1987, 26, 846.

Pimentel G. C., J. Chem. Phys. 1951, 19, 446.

Maintz S., Deringer V. L., Tchougréeff A. L., Dronskowski R., J. Comput. Chem. 2016, 37, 1030. PubMed PMC

Osman H. H., Otero‐de‐la‐Roza A, Rodrıguez‐Hernandez P., Munoz A., Javier Manjon F., ChemTxiv 2023, 69, 1327.

Alcock N. W., Bonding and Structure, Structural Principles in Inorganic and Organic Chemistry, Ellis Horwood, New York, London: 1990.

Rundle R. E., J. Am. Chem. Soc. 1947, 69, 1327.

Arora R., Waghmare U. V., Rao C. N. R., Adv. Mater. 2023, 35, 2208724. PubMed

Peierls R., More Surprises in Theoretical Physics, Princeton University Press, Princeton, NJ: 1991.

a) Schön C.‐F., Van Bergerem S., Mattes C., Yadav A., Grohe M., Kobbelt L., Wuttig M., Sci. Adv. 2022, 8, eade0828; PubMed PMC

b) Guarneri L., Jakobs S., Von Hoegen A., Maier S., Xu M., Zhu M., Wahl S., Teichrib C., Zhou Y., Cojocaru‐Mirédin O., Raghuwanshi M., Schön C.‐F., Drögeler M., Stampfer C., Lobo R. P. S. M., Piarristeguy A., Pradel A., Raty J.‐Y., Wuttig M., Adv. Mater. 2021, 33, 2102356. PubMed PMC

Anderson P. W., Phys. Rev. 1958, 109, 1492.

Mott N. F., Rev. Mod. Phys. 1968, 40, 677.

Di Sante D., Fratini S., Dobrosavljevic V., Ciuchi S., Phys. Rev. Lett. 2017, 118, 036602. PubMed