Evarestov Robert A, Kuzmin Alexei
Department of Quantum Chemistry, Saint Petersburg State University, St. Petersburg, Russian Federation.
Institute of Solid State Physics, University of Latvia, Riga, Latvia.
J Comput Chem. 2020 May 30;41(14):1337-1344. doi: 10.1002/jcc.26178. Epub 2020 Feb 24.
Pressure-induced insulator-to-metal transition (IMT) has been studied in the van der Waals compound iron thiophosphate (FePS ) using first-principles calculations within the periodic linear combination of atomic orbitals method with hybrid Hartree-Fock-DFT B3LYP functional. Our calculations reproduce correctly the IMT at ∼15 GPa, which is accompanied by a reduction of the unit cell volume and of the vdW gap. We found from the detailed analysis of the projected density of states that the 3p states of phosphorus atoms contribute significantly at the bottom of the conduction band. As a result, the collapse of the band gap occurs due to changes in the electronic structure of FePS induced by relative displacements of phosphorus or sulfur atoms along the c-axis direction under pressure.
利用具有杂化Hartree-Fock-DFT B3LYP泛函的原子轨道周期线性组合方法中的第一性原理计算，对范德华化合物硫代磷酸铁（FePS）中的压力诱导绝缘体-金属转变（IMT）进行了研究。我们的计算正确地再现了约15 GPa时的IMT，同时伴随着晶胞体积和范德华间隙的减小。通过对投影态密度的详细分析，我们发现磷原子的3p态在导带底部有显著贡献。因此，在压力下，由于磷或硫原子沿c轴方向的相对位移引起的FePS电子结构变化，导致带隙崩塌。
