Theoretical simulation of phase change materials such as Ge-Sb-Te has suffered from two methodological issues.On the one hand,there is a lack of efficient band gap correction method for density functional theory that ...Theoretical simulation of phase change materials such as Ge-Sb-Te has suffered from two methodological issues.On the one hand,there is a lack of efficient band gap correction method for density functional theory that is suitable for these materials in both crystalline and amorphous phases,while maintaining the computational complexity comparable to local density approximation.On the other hand,analysis of the coordination number in amorphous phases relies on an integration involving the radial distribution function,which adds to the complexity.In this work,we find that the shell DFT-1/2 method offers overall band gap accuracy for phase-change materials comparable to that of the HSE06 hybrid functional,while its computational cost is orders of magnitude lower.Moreover,the mixed length-angle coordination number theory enables calculating the coordination numbers in the amorphous phase directly from the structure,with definite outcomes.The two methodologies could be helpful for high-throughput simulations of phase change materials.展开更多
基金supported by the National Science and Technology Major Project of China(Grant No.2022ZD0117600)the National Natural Science Foundation of China under Grant No.12474230.
文摘Theoretical simulation of phase change materials such as Ge-Sb-Te has suffered from two methodological issues.On the one hand,there is a lack of efficient band gap correction method for density functional theory that is suitable for these materials in both crystalline and amorphous phases,while maintaining the computational complexity comparable to local density approximation.On the other hand,analysis of the coordination number in amorphous phases relies on an integration involving the radial distribution function,which adds to the complexity.In this work,we find that the shell DFT-1/2 method offers overall band gap accuracy for phase-change materials comparable to that of the HSE06 hybrid functional,while its computational cost is orders of magnitude lower.Moreover,the mixed length-angle coordination number theory enables calculating the coordination numbers in the amorphous phase directly from the structure,with definite outcomes.The two methodologies could be helpful for high-throughput simulations of phase change materials.
