MSST

Dear all,

I saw the example script in the MSST directory which have used metal unit. My question is that if I use real unit (because I have some restart file which was in real unit during equlibration) then in case of “q” , “tscale” value how it should be the unit conversion?

From doc page I got: “To perform a simulation, choose a value of q that provides volume compression on the timescale of 100 fs to 1 ps”

and in case of tscale, is it unitless ?

Any reply would be a help.

Another two questions:

1> My sample was well equlibriated at 300 k but as soon as the fix msst applied it starts from T= 196 K. What may be the explanation ?

2> In real unit my fix msst was : “fix msst all msst z 0.1 q 100 mu 3e2 tscale 0.01”

i.e. the Shock velocity was 10 Km/sec but the time dependency of volume states that the volume is compressing very slowly.

My system was water(SPC/E) with dimension 100 A cube and timestep is 0.5 fs.

The dhugoniot temperature drift is small enough but dReleigh fluctuation is very large.

Which is the best way initially to monitor from the result that ensure my simulation was make sense ?

Thanks for your help.

Unit conversions are documented in the units command.
Luckily distance and mass, and thus q, have the same unit for real and metal. Unitless quantities are not affected.

Sorry, I missed the dimension documented in MSST page. The actual problem was the dimension of “q”, I saw it is documented in MSST page. Now it’s clear… :slight_smile: