Internal enegy & heat

Dear All,

I’m going to calculate the generated heat due to bond breaking in a group of atoms. I want to monitor the variation of the internal energy on this group of atoms to calculate the generated heat. Can “compute ke/atom and pe/atom” be used for this purpose? or is there any better way?

And how about measuring the tempearture rise and using continuum thermal transport equations?

Thanks in advance,

Best regards,

Dear All,

I'm going to calculate the generated heat due to bond breaking in a group
of atoms. I want to monitor the variation of the internal energy on this
group of atoms to calculate the generated heat. Can "compute ke/atom and
pe/atom" be used for this purpose? or is there any better way?

​in typical classical MD simulations, bonds don't break. they are an input
parameter. some (usually manybody) ​potentials determine bonding patterns
on the fly, but here bonds would only break, if you first add some energy
into the system in some shape or form. to have a system "generate heat",
would require an exothermic reaction happening and the system would have to
be metastable, and it would need some trigger (heat/light/radicals) to
initiate the reaction.

compute ke/atom and pe/atom do what the documentation say they do, however,
whether they are applicable for your problem is up to whether that is
applicable to your simulation or model. that is for you to find out.

And how about measuring the tempearture rise and using continuum thermal
transport equations?

​have you looked at the USER-ATC pak​age?

axel.

Heat tends to be an ugly beast in thermodynamics. Heat is not equivalent to internal energy (unless closed system with no work done on it). I suggest you look into the simplest case, i.e., molecular fission, to see how chemists deal with heat calculations in such systems. Then you’ll have to figure out how that extends to your particular case.
Carlos