Ab initio crystal structure prediction of magnesium (poly)sulfides and calculation of their NMR parameters.

Title Ab initio crystal structure prediction of magnesium (poly)sulfides and calculation of their NMR parameters.
Authors G. Mali
Journal Acta Crystallogr C Struct Chem
DOI 10.1107/S2053229617000687
Abstract

Ab initio prediction of sensible crystal structures can be regarded as a crucial task in the quickly-developing methodology of NMR crystallography. In this contribution, an evolutionary algorithm was used for the prediction of magnesium (poly)sulfide crystal structures with various compositions. The employed approach successfully identified all three experimentally detected forms of MgS, i.e. the stable rocksalt form and the metastable wurtzite and zincblende forms. Among magnesium polysulfides with a higher content of sulfur, the most probable structure with the lowest formation energy was found to be MgS2, exhibiting a modified rocksalt structure, in which S(2-) anions were replaced by S2(2-) dianions. Magnesium polysulfides with even larger fractions of sulfur were not predicted to be stable. For the lowest-energy structures, (25)Mg quadrupolar coupling constants and chemical shift parameters were calculated using the density functional theory approach. The calculated NMR parameters could be well rationalized by the symmetries of the local magnesium environments, by the coordination of magnesium cations and by the nature of the surrounding anions. In the future, these parameters could serve as a reference for the experimentally determined (25)Mg NMR parameters of magnesium sulfide species.

Citation G. Mali.Ab initio crystal structure prediction of magnesium (poly)sulfides and calculation of their NMR parameters.. Acta Crystallogr C Struct Chem. 2017;73(Pt 3):229233. doi:10.1107/S2053229617000687

Related Elements

Magnesium

Magnesium Bohr ModelSee more Magnesium products. Magnesium (atomic symbol: Mg, atomic number: 12) is a Block S, Group 2, Period 3 element with an atomic mass of 24.3050. The number of electrons in each of Magnesium's shells is [2, 8, 2] and its electron configuration is [Ne] 3s2. The magnesium atom has a radius of 160 pm and a Van der Waals radius of 173 pm. Magnesium was discovered by Joseph Black in 1775 and first isolated by Sir Humphrey Davy in 1808. Magnesium is the eighth most abundant element in the earth's crust and the fourth most common element in the earth as a whole. Elemental MagnesiumIn its elemental form, magnesium has a shiny grey metallic appearance and is an extremely reactive. It is can be found in minerals such as brucite, carnallite, dolomite, magnesite, olivine and talc. Commercially, magnesium is primarily used in the creation of strong and lightweight aluminum-magnesium alloys, which have numerous advantages in industrial applications. The name "Magnesium" originates from a Greek district in Thessaly called Magnesia.

Sulfur

See more Sulfur products. Sulfur (or Sulphur) (atomic symbol: S, atomic number: 16) is a Block P, Group 16, Period 3 element with an atomic radius of 32.066. Sulfur Bohr ModelThe number of electrons in each of Sulfur's shells is 2, 8, 6 and its electron configuration is [Ne] 3s2 3p4. In its elemental form, sulfur has a light yellow appearance. The sulfur atom has a covalent radius of 105 pm and a Van der Waals radius of 180 pm. In nature, sulfur can be found in hot springs, meteorites, volcanoes, and as galena, gypsum, and epsom salts. Sulfur has been known since ancient times but was not accepted as an element until 1777, when Antoine Lavoisier helped to convince the scientific community that it was an element and not a compound.

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