Dear all

I have two questions with respect to the definition of energy in DPD

simulation.

1. I think the definition of the kinetic energy for N particle system is

defined as

\sum_{i=1}^N \frac{m}{2}(v_i^x*v_i^x+v_i^y*v_i^y+v_i^z*v_i^z).

But I wonder the data obtained by lammps is not so.

It may be devided by N.

Is it true?

I obtain the data by adding the following line:

thermo_style custom step ke

2. I cannot find the definition of the potential energy in lammps Manual.

Obviously the value of potential energy is dependent on the zero point.

What is the definition of the zero point in DPD simulation?

In other words, what is the definition of the DPD-potential?

I obtain the data by adding the following line:

thermo_style custom step pe

or

thermo style custom step evdwl

Thank you.

Best regards.