Chemistry Reference
In-Depth Information
μ*
2
= 1
μ*
2
= 2
0.08
0.08
0.07
0.07
0.06
0.06
0.05
0.05
0.04
0.04
0.03
0.03
0
0.2
0.4
0.6
0.8
1
0
0.2
0.4
0.6
0.8
1
x
2
x
2
μ*
2
= 3
0.12
0.1
0.08
0.06
0.4
0
0.2
0.4
0.6
0.8
1
x
2
FIGURE 6.7
Values of ρ
k
B
T
κ
T
for LJ/Stockmayer mixtures versus the mole fraction of
Stockmayer particles,
x
2
, for dipole moments of (a) μ*
2
= 1, (b) μ*
2
= 2, and (c) μ*
2
= 3, derived
from the Gross/Vrabec EOS (⎯) (From J. Gross and J. Vrabec, 2006, An Equation-of-State
Contribution for Polar Components: Dipolar Molecules,
American Institute of Chemical
Engineers Journal,
52, 1194), compared with results from our MD-Verlet (◻), truncation
(o) (From S. Weerasinghe and P. E. Smith, 2003b, Kirkwood-Buff Derived Force Field for
Mixtures of Acetone and Water,
Journal of Chemical Physics,
118, 10663); and distance-
shifting (∇) methods (From B. Hess and N. F. A. van der Vegt, 2009, Cation Specific Binding
with Protein Surface Charges,
Proceedings of the National Academy of Sciences of the
United States of America
, 106, 13296).
6.4.7 a
queous
a
lcohol
m
ixTures
The major goal is to establish an integration method that accurately predicts activity
coefficient derivatives, partial molar volumes, and isothermal compressibilities from
simulations of molecular mixtures with atom-atom interaction models. This section
focuses on such applications with results compared to values derived from correla-
tions of experimental data. It should be noted that the accuracy also depends on the
validity of the molecular force fields and reliability of experimental data. As with
the analysis of the LJ/Stockmayer mixtures, the simple truncation (Weerasinghe and
Smith 2003b) and distance-shifting methods (Hess and Van der Vegt 2009) were
employed to evaluate the same properties. Simple truncation averaging of the integral
