# Thread: Van der Waals force (Lenard-Jones)

1. Hi everyone

I'd like to know the Lennard-Jones potential energy is just for symmetric particles or we can use it for asymmetric forces too? If not how can I define the potential energy between two asymmetric particles?

Thanks

2. Originally Posted by Ferra
Hi everyone

I'd like to know the Lennard-Jones potential energy is just for symmetric particles or we can use it for asymmetric forces too? If not how can I define the potential energy between two asymmetric particles?

Thanks
What in the hell does this have to do with either special or general relativity ? Also, why do you think that the empirical model has any assumption of symmetry ? What is an asymmetric force ? (a violation of Newton's Third Law perhaps ?)
Are you sober ?

3. Originally Posted by DrRocket
What in the hell does this have to do with either special or general relativity ? Also, why do you think that the empirical model has any assumption of symmetry ? What is an asymmetric force ? (a violation of Newton's Third Law perhaps ?)
Are you sober ?
I really appreciate if you respect others.. I thought it's an academic and scientific forum with some academic members.. Suppose I'm not familiar with this subject, you are not responsible to answer all the questions in this forum if you don't have the patience. By the way, by asymmetric force I mean when i has influence on j but not vice-versa. For example I'd like to know two nano structures that have different size will interact with each other equally?

4. Originally Posted by Ferra
I really appreciate if you respect others.. I thought it's an academic and scientific forum with some academic members.. Suppose I'm not familiar with this subject, you are not responsible to answer all the questions in this forum if you don't have the patience. By the way, by asymmetric force I mean when i has influence on j but not vice-versa. For example I'd like to know two nano structures that have different size will interact with each other equally?
You can respect others by presenting clear questions about which you have taken the trouble to think a bit, thereby jutifying the time and trouble that is required to present a response. Remember, it is you who are requesting the benefits of thhe expertise of others, at no cost to you. If you do not feel it obligatory on you to invest that effort, then please feel free to go straight to hell.

5. Originally Posted by Ferra
By the way, by asymmetric force I mean when i has influence on j but not vice-versa. For example I'd like to know two nano structures that have different size will interact with each other equally?
By that definition there are no asymmetric forces, since Newton's Third Law says that any two objects exert force on each other which are equal in size but opposite in direction. If you identify all the forces accurately, two nano structures must exert equal but opposite forces on each other. However, if they are in a medium, there is no requirement that the medium exert equal forces on each of them.

6. Originally Posted by mvb
By that definition there are no asymmetric forces, since Newton's Third Law says that any two objects exert force on each other which are equal in size but opposite in direction. If you identify all the forces accurately, two nano structures must exert equal but opposite forces on each other. However, if they are in a medium, there is no requirement that the medium exert equal forces on each of them.