We briefly review the isothermal-isobaric ensemble partition function corre
ctly derived by Corti and Soto-Campos [J. Chem. Phys. 108, 7959 (1998)] fro
m the view point of usual simulations in which the external bath of a syste
m is appropriately approximated. We show that, for the homogeneous system,
the partition function can be reduced to the result of Attard [J. Chem. Phy
s. 103, 9884 (1995)] which was criticized by Corti and Soto-Campos. We conc
lude that the volume scale cannot be defined in general but in some particu
lar cases and the recently controverted volume scales are those of the case
s. We also confirm the validity of Brown's [Mol. Phys. 1, 68 (1958)] partit
ion function which has never been used in simulations before, by demonstrat
ing that it is equivalent to the one of Corti and Soto-Campos. (C) 2001 Ame
rican Institute of Physics.