Fig. 4: The influence of disorder on Debye-Waller factors (DWF) and deformation electron density map ∆ρ^EXP (r).

a DFT-relaxed supercell structure of disordered FePd. b Displacements of Fe and Pd atoms in eight (100) planes from their averaged lattice positions. The arrows are proportional to the displacement vector. c Histogram of \({B}_{{\mbox{static}}}^{{\mbox{Fe}}}\) and \({B}_{{\mbox{static}}}^{{\mbox{Pd}}}\) as calculated using the static lattice distortion. d Comparison between the difference of ordered and disordered DWF (\({B}_{{\mbox{iso}}}\) - \({B}_{11}\), \({B}_{{\mbox{iso}}}\) - \({B}_{33}\)), and the static component \({B}_{{\mbox{static}}}\) caused by lattice distortion. e Comparison of the difference between experimental and IAM \({F}_{g}^{X}\) for disordered and ordered FePd. f, g \(\triangle {\rho }^{{\mbox{EXP}}}\left(r\right)\) of (f) disordered and (g) ordered FePd constructed using low-order \({F}_{g}^{X}{{{\rm{s}}}}\) up to \({F}_{200}\). The upper parts are \(\triangle {\rho }^{{\mbox{EXP}}}\left(r\right)\) on the (110) plane, where the first black line (white arrows) has zero electron density. Black lines within yellow-orange regions and white lines within deep purple-magenta regions represent positive and negative electron density, respectively. The difference between two adjacent contours is 0.01 e/ų. The tetrahedral and octahedral interstitial sites within an FCC unit cell are marked with grey and yellow spheres, respectively. The tetrahedral sites of electron accumulation are indicated by black arrows. Source data are provided as a Source Data file.