2023/12/12 by Härkönen, Ville J.
#Chemical Physics (physics.chem-ph) #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci)
paper · doi:10.48550/arxiv.2312.07411
We compute the ab-initio electron density beyond the Born-Oppenheimer approximation in crystalline LiH and LiD with density functional methods. We report significant beyond Born-Oppenheimer corrections to electron density in the vicinity of nuclei equilibrium positions. We thus verify the breakdown of the Born-Oppenheimer approximation, as earlier suggested on experimental grounds. A reasonable agreement between the experimental and computational results is found. The results indicate the existence of beyond Born-Oppenheimer effects in solids at normal pressures and suggest that these effects can be significant also in solids containing elements other than hydrogen as well.