and compare them with previous calculations.

![( Color on line) Comparison of the pn-QRPA and FFN [@Fuller82] $\beta^{+}$ decay rates of $^{57}$Zn nucleus as a function of temperature for selected densities (in units of $g.cm^{-3}$ shown in legends) in stellar matter.[]{data-label="fig4"}](fig.4.eps){width="3.3in" height="4.3in"}

To the best of author’s knowledge, there are no shell model weak rates available in the literature for $^{57}$Zn nucleus. Therefore, pn-QRPA rates were compared with the pioneer work of Fuller et al. [@Fuller82]. This comparison for the $\beta^{+}$ decay and electron capture rates are shown in Fig. \[fig4\], and Fig. \[fig5\], respectively. Fig. \[fig4\] shows that the pn-QRPA $\beta^{+}$ decay rates are in good comparison with the FFN rates. However at high stellar temperatures (T$_{9} [K] = 30$) the FFN rates are almost twice the calculated rates. The authors in Ref. [@Fuller82] put no constraints on the threshold values of parent excitation energies while in the present calculation such constraints were incorporated through particle emission processes [@Nabi04] which lead to the suppression of pn-QRPA $\beta^{+}$ decay rates at high stellar temperatures (when the probability of occupation of high-lying parent excited states increases substantially). Regarding the calculation of electron capture rates (Fig. \[fig5\]) one notes that at high 