Simply Scary

For $CaGeO_3$, $Z_m=20+32+8*3=76$ density $3.56\,gcm^{-3}$ and molar mass $160.7162\,gmol^{-1}$

$v_{boom}=3.4354*\cfrac{3560}{76}=160.92\,ms^{-1}$

$T_{v\,p}=160.92^2*\cfrac{160.7162*10^{-3}}{2*8.3144}=250.28\,K$  or $-22.87\,^oC$

which is still way low even with the use of $v_p$ instead of $v_{rms}$.  Clearly,

$T_{v\,p}$  or $T_{boom}\propto density^2$   and

$Conductivity\,at\,T_{v\,p}\gt Conductivity\,at\,T_{boom}$ due to more fraction of particles attaining $v_{boom}$ at $T_{v\,p}$.  Conductivity is maximum at $v_p=v_{boom}$ when $Temperature=T_{v\,p}$.

The simple $y=x^2$ relation of $T_{v\,p}$ and $T_{boom}$ with density is surprising given all the write-ups in superconductivity.