current simulation needs fixin

[Ian-Harreschou]

1. still returning "NaN" in the function for finding maximum film thickness
2. viridis colormap indexing breaks for certain temperature ranges, current fix is indexing with [20*i] and praying the numbers work out just fine

[Ian-Harreschou]

3. in adding a "total pressure" and "mole fraction of SiCl4" slider, there are some combinations of values which return an error about finding the maximum of an empty array

the error was occurring with taking the maximum of an array while the mask was specifically non_negative = \delta[\delta .> 0] when some of the films didn't grow so therefore didn't meet the condition

4. since we now have an upper limit of system pressure (760 mmHg), our films are now showing significantly less growth --> fix with optimized equilibrium Kp?