  We have shown that recent report concerning the first-order phase transitions
in the large-spin systems is inaccurate. A kinetic numerical method for making
calculations of the transition rate in a bistable system as a function of
temperature has been evolved and a new critical value of the transition field
(h=0.891) has been found. A physical mechanism caused transition from quantum
to classical behavior has been discussed.

Mesoscale and Nanoscale Physics