Barium Sulfide under Pressure: Discovery of Metastable Polymorphs and Investigation of Electronic Properties on ab Initio Level

Barium sulfide (BaS) is an important precursor to other barium compounds with applications from ceramics and flame retardants to luminous paints and additives, and recent research shows potential technological applications in electrical and optical devices. Under normal conditions, BaS crystallizes in the NaCl type of structure, and with the increase in pressure BaS undergoes a structural phase transition to a CsCl type modification. This study presents modeling of barium sulfide under pressure with special focus on structural aspects and electronic properties. We predict metastable BaS polymorphs which have not yet been observed in the experiment or in previous calculations, and we investigated their vibrational and thermodynamical properties. Furthermore, we investigate the electronic properties of experimentally known structures as well as novel predicted modifications of BaS on ab initio level using Hartree–Fock, GGA-PBE, and the hybrid B3LYP functional. In this way, we address new possibilities of synthesizing BaS and possible band gap tuning which can have great applications in optoelectrical technologies

Least-squares means (LSM) with their corresponding standard errors (SE) of the frequency of LDA on the underlying logit scale for the genotypes of the SNPs FN298674:g.90T>C and FN298674:g.1891insG and the contrasts among the LSMs with their test statistics and P-values.

<p>Genotypic means for the frequency of LDA were estimated through LSMs in a mixed logit model correcting for data stratification.</p

All identified polymorphisms with their location within <i>motilin</i> (<i>MLN</i>).

*<p>IRD labeled.</p><p>Informative (I) polymorphisms are indicated by a plus sign. The primer pairs used are given with their annealing temperatures (AT) and product sizes (PS).</p

Association study for LDA using SNPs within <i>motilin</i> for 1,136 German Holstein cows.

<p>For each SNP, minor allele frequencies (MAF), the MAF allele, odds ratios (OR) with their 95% confidence intervals (CI), polymorphism information content (PIC), and heterozygosity (HET) are given. Furthermore, −log₁₀P-values (P) are given for genotype (gt), allele, among homozygotes (hom) and for genotype after correcting the data for stratification (strat).</p

Results of the expression analysis for FN298674:g.90T>C within <i>motilin</i> (<i>MLN</i>).

<p>The mean relative expression levels of <i>MLN</i> with their standard errors are given for the wildtype genotype T/T, the heterozygously (C/T) and the homozygously mutated genotype (C/C) standardized on the mean of the genotype T/T. Furthermore, the F-values and P-values for the differences in mean relative expression levels among the genotype T/T versus the genotypes C/T and C/C as well C/T versus C/C are given. <i>RPL4</i> was used as housekeeping gene.</p

Mutation within the bovine <i>motilin (MLN)</i> gene associated with LDA.

<p>Sequence of <i>MLN</i> surrounding the FN298674:g.90T>C SNP for the wildtype (control cow) and the mutated allele (LDA-affected cow) as well as the 3′ end of the predicted <i>MLN</i> promoter, the 5′ start sequence of the non-coding first exon of <i>MLN</i> and the NKX2-5 transcription factor binding site are shown. Furthermore, chromatograms of this section are given for each one of the homozygous wildtype, heterozygous and homozygous mutant individuals.</p