Abstract
We present an alternative method for interpreting the velocity autocorrelation function (VACF) of a fluid with application to extracting the entropy in a manner similar to the methods developed by Lin [J. Chem. Phys. 119, 11792 (2003)]JCPSA60021-960610.1063/1.1624057 and improved upon by Desjarlais [Phys. Rev. E 88, 062145 (2013)]PLEEE81539-375510.1103/PhysRevE.88.062145. The liquid VACF is decomposed into two components, one gas and one solid, and each contribution's entropic portion is calculated. However, we fit both the gas and solid portions of the VACF in the time domain. This approach is applied to a single-component liquid (a two-phase model of liquid Al at the melt line) and two different two-component systems: a superionic-to-superionic (bcc to fcc) phase transition in H2O at high temperatures and pressures and a metastable liquid state of MgO. For all three examples, comparisons to existing results in the literature demonstrate the validity of our alternative.
| Original language | English |
|---|---|
| Article number | 042119 |
| Journal | Physical Review E - Statistical, Nonlinear, and Soft Matter Physics |
| Volume | 93 |
| Issue number | 4 |
| DOIs | |
| State | Published - Apr 15 2016 |
| Externally published | Yes |
Funding
E.R.M. is grateful for useful and inspiring discussions with Mandy Bethkenhagen and Martin French. In addition, E.R.M. thanks Michael Desjarlais for providing his data on aluminum for comparison. The authors gratefully acknowledge support from science campaigns 1 and 4 as well as the Advanced Simulation and Computing Program. Los Alamos National Laboratory is operated by Los Alamos National Security, LLC for the National Nuclear Security Administration of the US Department of Energy under Contract No. DE-AC52-06NA25396.
| Funders | Funder number |
|---|---|
| U.S. Department of Energy | DE-AC52-06NA25396 |
| National Nuclear Security Administration |