Find points where the self Van Hove crosses the Gaussian approximation to the self Van Hove.
compare_gaussian <output file> <displacement time index (optional)>
<target>
Requires prior calculation of self van hove in the same run. If only two arguments are given, this analysis first calculates the non-Gaussian parameter and used the time spacing corresponding to the peak in the nGP. If a third argument is given, self Van Hove will be compared to the Gaussian approximation at the time index given.