Electronic correlation strength of Pu

An electronic quantity, the correlation strength, is defined as a necessary step for understanding the properties and trends in strongly correlated electronic materials. As a test case, this is applied to the different phases of elemental Pu. Within the $\mathit{GW}$ approximation we have surprisingly found a “universal” scaling relationship, where the $f$-electron bandwidth reduction due to correlation effects is shown to depend only on the local density approximation bandwidth and is otherwise independent of crystal structure and lattice constant.

Figure 1

Plot of $w_{\mathrm{rel}}=W_f\left(GW\right)/W_f\left(\text{LDA}\right)$ versus volume, $V$, per atom, for the $\gamma$, fcc, bcc, sc, and ps-$\alpha$ [pseudo-$\alpha$, an approximate $\alpha$ phase (Ref. 53)] crystal phases of Pu. Note that the sc (simple cubic) is a hypothetical structure for Pu. The small, vertical bars at the top of the figure mark the experimentally observed atomic volumes (Ref. 54).

Figure 2

Plot of $w_{\mathrm{rel}}=W_f\left(GW\right)/W_f\left(\text{LDA}\right)$ versus $W_f$(LDA) for the $\gamma$, fcc, bcc, sc, and ps-$\alpha$. The dashed red line represents the fit of Eq. (5). The small, vertical bars at the top of the figure mark the values of $W_f$(LDA) calculated at the experimental volumes of the five Pu phases (Ref. 54).

Figure 3

Trends in Pu properties as a function of correlation strength $C$, including (a) volume per atom (Ref. 54), (b) sound velocity (Ref. 57), and (c) resistivity (Ref. 57).

Figure 4

$C$ from $\mathit{GW}$ theory versus $1/W_f\left(\text{LDA}\right)$. The data for Co, Rh, and Ir are for the $3d$, $4d$, and $5d$ bandwidths, respectively. The small, vertical bars at the top of the figure mark the values of $W_f{\left(\text{LDA}\right)}^{-1}$ calculated at the experimental volumes of the five Pu phases (Ref. 54).