Critical comparison of classical and quantum mechanical treatments of the phase equilibria of water
The Gibbs ensemble Monte Carlo simulation technique was used to compare the phase equilibria of the rigid TIP4P water model [J.\ Chem.\ Phys.\ {\bf 79}, 926, (1983)] utilizing classical and quantum statistical mechanical treatments. The quantum statistical mechanical treatment generally resulted in lower liquid densities and higher vapor densities, showing a narrowing in the phase envelope. As a result, the calculated critical temperature and normal boiling point were higher from the quantum simulations than the classical by 20~and 17~K, respectively, but the critical densities were very close. A semiclassical treatment, involving a low order expansion in Plank's constant, resulted in densities and vapor pressures that fluctuated between the values for the classical and quantum statistical mechanics values, with no definite agreement with either.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 878256
- Report Number(s):
- PNNL-SA-46206; JCPSA6; KC0301020; TRN: US200611%%66
- Journal Information:
- Journal of Chemical Physics, 124:114505, Vol. 124; ISSN 0021-9606
- Country of Publication:
- United States
- Language:
- English
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