19990812: $Zr_{250}Ce^{4+}_{50}Ce^{3+}_{200}O_{900}(V^{\cdot \cdot }_O)_{100}$ with different starting configuration

GOAL

Identical to 19990810 (31), but different starting configuration, to see the reproducibility of the oxygen diffusion coefficient.

Results

Notes:

• The starting configurations for 19990810 and 19990812 were created with the dlsub program, but no constraints were applied.
• The starting configurations were differently randomized (i.e. the randomizations seeds in the dlsub input were different) and I could verify that the $V_{O}^{\cdot\cdot}-V_{O}^{\cdot\cdot}$ RDF's were actually different: I don't report them here because I'm lazy)
• I realized too late that, notwithstanding the different composition with respect to the calculations reported in 19990805, I did not recalculate the lattice parameter. The lattice parameter which should have been used in these two calculations, obtained with the two procedures reported in 19990614 (16.2), is:

  GULP	$5.449143$	$\mbox{\textit{\AA}}$
  Vegard	$5.43402073$	$\mbox{\textit{\AA}}$

  These two values are considerably larger than the value I actually used: $5.337004\;\mbox{\textit{\AA}}$

The following compares the MSD plots for current and 19990810 (31) calculations. Dashed lines represent linear fits to the MSD plot. In the case of 19990812, two fits are shown: the first refers to the entire time range (excluding the very first region, of course) while the second was performed on the second, linear part of the MSD plot only.

The following compares the fit results and the oxygen diffusion coefficients for the two calculations: