Fig. 4: Schematic diagram for calculating the on-site Si atomic energy difference.
a The schematic diagram illustrating the division of distinct regions (with Si atoms represented by large yellow balls) to obtain the on-site Si atomic energies of \(\triangle {E}_{{Si}1,{b}}\), \(\triangle {E}_{{Si}2,{b}}\), \(\triangle {E}_{{Si}/{Li}-{Si},{i}}\) and \(\triangle {E}_{a-{{Li}}_{x}{Si}}\) in the two different bulk Si regions, the Si/Li-Si interface region and the a-LixSi region. The four define on-site Si atomic energies represent the energy change upon removal of one Si atom from the left bulk Si region, the bulk Si region near the Si/Li-Si interface, the Si/Li-Si interface region, and the a-LixSi region near the right Li-Si/Li interface, respectively. b Diagram of the changes of the average on-site Si atomic energies \(\overline{\triangle {E}_{Si1,{b}}}\), \(\overline{\triangle {E}_{Si2,{b}}}\), \(\overline{\triangle {E}_{Si/Li-Si,i}}\) and \(\overline{\triangle {E}_{a-{Li}_{x}Si}}\) along the z-axis for the four interface models. Random selection of Si sites for doing statistical averages is introduced in the next methodology section.
