HI LAMMPS users,

I started learning SMD,

Initially placed two Argon separated by 3 Angstorm, and runned smd at tem 1K,

printed 5th column and 7th column of fix_id, But I can see PMF increasing continuously,

plotted the distance(5th column) vs PMF( 7th column) , I’m unable to get the PMF of two Argon atoms.

input file

group one id == 1
group two id == 2

fix 1 one smd cvel 500.0 0.00000004 couple two auto auto auto 0.0

IS anything wrong with above three lines…

I need help please…

Thanks in advance…

I don't think that you have a good test system for this method. Have a look at the papers referenced in the documentation and others discussing free energy methods that came after.

Hi Axel sir,

I tried with different molecule,

took two benzene rings placed at 3 Angstorm, but even now, i see still PMF increasing,

I plotted equilibrium distance of spring and PMF accumulated,

will that be the free energy profile ???

I told you before these are bogus test systems. Haven’t you read any papers on the method?