Ethane homepage
3. Transport Properties
The shear viscosity η and
diffusivity D obtained from molecular dynamics simulations are presented here. The
viscosity was calculated using the Green-Kubo relation [1]:
where the subscripts αβ=
xy, yx, and zy. Averaging over the three possible shear stresses was
performed to obtain better statistics.
The diffusivity was
obtained using the Einstein relation, valid at long time times t,
Basic simulation parameters are given below.
| METHOD: |
NVE
molecular dynamics |
| N: |
500 |
| TRUNCATION:
LJ-
|
L/2 + standard long range corrections
|
| Δt: |
0.5 fs |
| Trajectory
Length: |
2.5E3 ps |
Shear
Viscosity and Diffusivity:
|
|
| T (K) |
ρ
(kg/m3)
|
η
(Pa s) * |
D (m2/s) |
184
|
5.262E+02 |
1.31E-04 |
6.48E-09 |
| 194 |
5.262E+02 |
1.29E-04 |
6.94E-09 |
| 224 |
5.262E+02 |
1.31E-04 |
8.18E-09 |
| 243 |
5.262E+02 |
1.24E-04 |
8.74E-09 |
| 245 |
5.262E+02 |
1.13E-04 |
8.81E-09 |
| 288 |
5.262E+02 |
1.21E-04 |
1.03E-08 |
| 289 |
5.262E+02 |
1.19E-04 |
1.04E-08 |
| 289 |
4.571E+02 |
8.26E-05 |
1.55E-08 |
| 290 |
4.210E+02 |
7.02E-05 |
1.78E-08 |
| 290 |
3.518E+02 |
3.87E-05 |
2.71E-08 |
| 290 |
7.115E+01 |
1.05E-05 |
|
| 294 |
4.420E+01 |
9.98E-06 |
2.04E-07 |
| 291 |
2.932E+01 |
1.19E-05 |
2.83E-07 |
| 289 |
1.735E+01 |
1.06E-05 |
3.53E-07 |
| 284 |
1.735E+01 |
1.05E-05 |
3.66E-07 |
|
* The relative uncertainties in the liquid-phase
shear viscosities are in the range of 3 - 5 %. Those for the vapor are
in the range of 5 - 10 %.
REFERENCES
[1] B. Chen and J. I. Siepmann, J. Phys. Chem. B
105, 11275, (2001).
[2] B. Chen and J. I. Siepmann, J. Phys. Chem. B
105, 11275 (2001).
[3] B. Chen, J. I. Siepmann, K. J. Oh, and M. L. Klein, J.
Chem. Phys.
115, 10903 (2001).
