Pressure enhanced negative thermal expansion in 2H CuScO₂ from first-principles calculations

Abstract

Negative thermal expansion (NTE) is interesting and finding materials with NTE is challenging. The effects of pressure on thermal expansion properties of NTE materials and tuning of NTE are of...

Unexpected low thermal expansion coefficients of pentadiamond

“…5i). Therefore, the mechanism of NTE in pentadiamond is similar to CuScO2, 60,61 and the schematic is shown in Fig. 5j.…”

Exploring negative thermal expansion materials with bulk framework structures and their relevant scaling relationships through multi-step machine learning

“…149,150 Since the DFT calculations cannot take into account the contribution of entropic elasticity to NTE, there may be some deviations in calculating CNTE using both the static DFT calculations and ab initio molecular dynamics simulation with the machine learning interatomic potentials (MLIPs), compared to the experimental results. Nevertheless, our previous DFT calculations of CNTE for some NTE materials with framework structures (such as fluorides, [151][152][153][154] oxides, [155][156][157] cyanides 158 and PBAs [159][160][161] still have achieved comparable results with experiments, and it is shown that using the DFT calculations as a roughly qualitative criterion to judge whether a material has NTE characteristics should be reasonable and unquestionable. Due to the fact that the first-principles calculation of the CNTE will require a lot of computer time, especially for oxide systems with a large number of atoms in the primitive cells and complex crystal structures, here, we select a few compounds with simple structures and small number of atoms in the primitive cell for calculation.…”