# Heat capacity in eDPD method when we have more than one material?

Hello All,

I am using LAMMPS version: LAMMPS (23 Jun 2022) and edpd method . In the a reference paper mentioned in the documentation there is an explanation about how to calculate the heat capacity of an edpd particle:

“Dimensionless variables that are suitable for interpretation of the results are introduced to carry out the simulations.
The temperature of reference T ∗ = 300 K is used to scale the temperatures, thus the temperatures ranging from 273 K to
373 K are represented by the dimensionless temperature T = 0.91 to 1.2433. The heat capacity of each eDPD particle is
normalized by the Boltzmann constant k∗
B given by C v = C ∗
v L∗3/ρk∗
B in which C ∗
v is the volumetric heat capacity of the
fluid, L∗ the length of reference, and ρ the number density of eDPD particles. For example, C ∗
v = 4.167 × 106 J m−3 K−1 for
water at 300 K and k∗
B = 1.381 × 10−23 J K−1, so given a length unit L∗ = 11 nm and ρ = 4.0 one gets C v = 1.0 × 105 for
the simulations. All the quantities without physical units are the dimensionless variables from now on”

This is from the following paper:

Based on the documentation and the referenced paper explanation, I could not figure out what do I need to put for Cv when I have more than one material (in my project CNT & water). I emailed Dr. Zhen Li from LAMMPS website’s email adresses, but the e-address is expired. Is there any suggestion about how I can find the required information (Cv for CNT and Water in edpd method)?

Thanks a lot,

I have had good success to track down researchers’ current affiliation and with that their email through either https://scholar.google.com/, https://orcid.org/, https://www.researchgate.net/, or https://www.linkedin.com/ (in that order). For as long as people remain active in research, they will keep publishing and update their information in at least one of these websites.