First-Principles Calculations of Structures and Electronic Properties of Solid Pentaerythritol under Pressure

Structures and electronic properties of the pentaerythritol (PE) crystal under volume compression up to 0.85V₀ are studied by E-V fitting method using density functional theory (DFT). The compression dependences of the cell volumes, lattice constants, and molecular geometries of solid PE are presented and discussed. It is found that the solid PE presents anisotropy along a- and c-axes, and the c axis is the most compressible. Decreasing anisotropy ratio (c/a) with elevating compression suggests an enhancement of the vdW interaction with increasing compression. The C--C and C--H bonds are significantly reduced under compression, which may be related to the sensitivity. The solid PE has indirect band gap (X-G) in the range of the researched compression and the band gap is decreased with compression.