Entertaining the Possibility of RT Superconductivity in LK-99

Abstract: An intuitive chemical perspective on the LK-99 material is outlined and supported by DFT calculations. A hidden flat Lead band that exhibits instability toward charge density wave formation is exposed. Electron transfer between Lead CDW/conduction bands and Cu$3$d$^9$/Cu$_3$d$^{10}$ impurity states is suggested to embody the observed phenomenology reminiscent of room temperature superconductivity. The inter-system electronic instability is reflected in a chemical instability involving 2Pb${10-x}$Cu$x$(PO$_4$)$_6$O => Pb${20-2x}$Cu${2x}$(PO$_4$)${12}$(O$_2$). Implications for tuning posttreatments as well as handling of the LK-99 material emerge.