SRD particles and lj units conversion

Hello all

i have a 3d system with srd particles. i have read manual and the most of messages in the mail list but i couldnt figure out how i should convert units from lj to real SI units when i have srd particles? i’ve seen the argon problem .in that case we have values of sigma and epsilon and mass from table of argon but when i have SRD particles with no interaction how i can convert units?it said that i should have mass and epsilon and sigma to get units of time and force and … but what is the unit of energy in my system?

thanks in advance


Do you have other non-SRD particles? If so, then

they do have a mass, epsilon, etc. So you those

to do the conversion. There is no energy term for

SRD/SRD interactions. If your system is pure SRD

particles, then the only energy is kinetic, i.e. due to

their temperature. For that purpose they do have mass = 1.0

in LJ units.

I’m CCing Dan Bolintineanu, who may have additional comments.


You can use the length of SRD bins (hgrid) as a length scale, mass of SRD particles as mass scale, and collision time as a time scale. The combination of those can get you energy scale, etc.