  A microscopic calculation of $\alpha$-cluster preformation probability and
$\alpha$ decay width in the typical $\alpha$ emitter $^{212}$Po is presented.
Results are obtained by improving a recent approach to describe $\alpha$
preformation in $^{212}$Po [Phys. Rev. C 90, 034304 (2014)] implementing
four-nucleon correlations (quartetting). Using the actually measured density
distribution of the $^{208}$ Pb core, the calculated alpha decay width of
$^{212}$Po agrees fairly well with the measured one.
