Scientists at EPFL discovered an unusual “Rule of Four” in electronic structure databases, where many materials unit cells consist of multiples of 4 atoms. The researchers called this recurrence the “Rule of Four” and began looking for an explanation.Initial Investigations” A very first user-friendly factor might come from the fact that when a traditional system cell (a larger cell than the primitive one, representing the full proportion of the crystal) is transformed into a primitive cell, the number of atoms is typically decreased by 4 times,” says Elena Gazzarini, a former INSPIRE Potentials fellow in the Laboratory of Theory and Simulation of Materials (THEOS) at EPFL and now at CERN in Geneva. “This is intriguing because the algorithm utilizes only regional rather than international balance descriptors, which suggests that there might be small chemical groups in the cells (still to be discovered) that might describe the guideline of 4,” states Gazzarini.Reference: “The guideline of four: anomalous distributions in the stoichiometries of inorganic substances” by Elena Gazzarrini, Rose K. Cersonsky, Marnik Bercx, Carl S. Adorf and Nicola Marzari, 12 April 2024, npj Computational Materials.DOI: 10.1038/ s41524-024-01248-z.
Researchers at EPFL found an unusual “Rule of Four” in electronic structure databases, where numerous materials system cells consist of multiples of 4 atoms. The researchers called this reoccurrence the “Rule of Four” and began looking for an explanation.Initial Investigations” A very first instinctive factor could come from the reality that when a standard system cell (a larger cell than the primitive one, representing the complete proportion of the crystal) is changed into a primitive cell, the number of atoms is normally lowered by 4 times,” states Elena Gazzarini, a previous INSPIRE Potentials fellow in the Laboratory of Theory and Simulation of Materials (THEOS) at EPFL and now at CERN in Geneva. “This is fascinating because the algorithm uses only local rather than global proportion descriptors, which recommends that there may be little chemical groups in the cells (still to be found) that might discuss the rule of 4,” states Gazzarini.Reference: “The guideline of four: anomalous distributions in the stoichiometries of inorganic compounds” by Elena Gazzarrini, Rose K. Cersonsky, Marnik Bercx, Carl S. Adorf and Nicola Marzari, 12 April 2024, npj Computational Materials.DOI: 10.1038/ s41524-024-01248-z.