Lennard Jones Potential & Kinetic Energy

In summary, the conversation discusses the use of a specific potential, the Lennard Jones potential, to model two particle interaction. The issue is trying to force the particles into the potential well at a separation distance of 2.5*10-8. The interpretation of the potential involves setting a total energy of -6.0*10-20 by giving the particles a kinetic energy of 3.95*10-20. The calculation of the velocity for the kinetic energy is not working, and it is suggested to use an inertial frame where one particle has 0 velocity. The conversation also mentions the possibility of working in higher dimensions and the need for a centrifugal term.
  • #1
relskhan
5
0
So I'm trying to model two particle interaction subject only to Lennard Jones potential. I have a specific potential I am using:
B3AADfbCIAEOi8o.jpg


My problem is forcing the two particles into the potential well. I have the particles at a separation distance of 2.5*10-8. The way I interpret this potential is that I can set a total energy of -6.0*10-20 by giving the particles a Kinetic Energy of 3.95*10-20 (Where Total Energy TE=KE + U or KE = TE - U => KE = -6.0*10-20 +9.95*10-20 = 3.95*10-20 , the -9.95*10-20 comes from U(2.5*10-8).

To set the kinetic energy I'm using 1/2 m (v12+v22). And giving particle 1 an initial velocity equal to some factor of particle 2's velocity.

Unfortunately, this is still not working. So I am either interpreting the different energy requirements on the diagram wrong - or not calculating the velocity for the KE correctly. Any ideas??
 
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  • #2
How many dimensions? In dimensions higher than 1 you'll need a centrifugal term.

Actually, I'm not sure if this answers your question.
 
  • #3
UVCatastrophe said:
How many dimensions? In dimensions higher than 1 you'll need a centrifugal term.

Actually, I'm not sure if this answers your question.
Good Point - I should have specified. This is all 1-D, I will 'upscale' to 3-D later, but for now, I just want the simplest model.
 
  • #4
What isn't working about it? It might be easier to work out in an inertial frame where one particle has 0 velocity.
 
  • #5
Calion said:
What isn't working about it? It might be easier to work out in an inertial frame where one particle has 0 velocity.
Well I didn't want to get into the details too far - I mostly want to make sure my interpretation of the Energies are correct. I could try starting the particle at 0 velocity - but - the potential will move it I'm sure.
 

1. What is the Lennard Jones Potential?

The Lennard Jones Potential is a mathematical model used to describe the interaction between two neutral atoms or molecules. It takes into account both the attractive and repulsive forces between the particles, and is commonly used in simulations of molecular dynamics.

2. How is the Lennard Jones Potential calculated?

The Lennard Jones Potential is calculated using the equation: V(r) = 4ε[(σ/r)^12 - (σ/r)^6], where r is the distance between the particles, ε is the depth of the potential well, and σ is the distance at which the potential is zero. This equation accurately describes the attractive and repulsive forces between particles at different distances.

3. What is the significance of the Lennard Jones Potential in thermodynamics?

The Lennard Jones Potential is significant in thermodynamics because it is used to model the intermolecular forces between particles, which play a crucial role in determining the properties of a substance such as phase transitions and changes in temperature and pressure.

4. What is the relationship between Lennard Jones Potential and Kinetic Energy?

The Lennard Jones Potential and Kinetic Energy are related through the Boltzmann distribution, which states that the average kinetic energy of a particle is directly proportional to the temperature of the system. The Lennard Jones Potential affects the potential energy of the particles, which in turn affects their kinetic energy and overall behavior.

5. What are some real-world applications of the Lennard Jones Potential?

The Lennard Jones Potential is used in various fields such as chemistry, physics, and material science to simulate the behavior of atoms and molecules in different environments. It is also commonly used in computer simulations to study the properties of substances and to design new materials with specific characteristics.

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