Talk:Lennard-Jones potential

message: One of the figures in this article is a Rayleigh-Taylor instability. It is in the computational physics box, but it seems irrelevant to me for this article. Any suggestions here?  — Preceding unsigned comment added by 145.94.187.200 (talk) 07:29, 21 August 2012 (UTC)
thread_title:  Rayleigh-Taylor instability 

message: According to the first equation and the x axis of the plot being in units of sigma, the minimum of potential in the figure should be r_m/sigma (not r_m)  — Preceding unsigned comment added by 129.237.99.102 (talk) 02:05, 26 March 2014 (UTC)
thread_title:  Inconsistency between the first plot and the LJ equation 

message: To write "LJ" as an index for a potential V ist to name the potential (and LJ is a mere name not a parameter), so one should have upright indexes. May someone please change this. Jjh1993 (talk) 14:43, 4 February 2015 (UTC)
replies: text: I just changed all non-variable subscripts to upright, that includes abbreviations for truncated, cutoff, etc. --Jkokorian (talk) 09:58, 2 September 2016 (UTC)
thread_title:  Indexes should be upright 

message: When variables are first introduced, their units should be explicitly mentioned. To me, as an electrical engineer 'potential' implies that the unit is Volt, but I've even seen Lennard-Jones potential curves with a 'potential' in 1/cm. Could someone please add the correct units? I would do it myself, but I don't know what they are... --Jkokorian (talk) 10:04, 2 September 2016 (UTC)
thread_title:  Variables should be declared with units 

message: σ and r_m are used in the LJ potential equations but later on in "Explanation", r_0 is used for the Buckingham potential without an explanation as to what it is. Is it σ, r_m or something else? r_0 is also used in "Alternative expressions", subsection "AB form" where is states that at r_0, V = − ε. This would mean, at least for this part, that r_0 = r_m and two different notations are used.  — Preceding unsigned comment added by Jvillatoro leal (talk • contribs) 09:58, 19 January 2018 (UTC)
thread_title:  Notation inconsistencies 

message: I do not understand how 1/r^12 may model a Pauli repulsion. I have searched INTERNET without results, then I have tried the formulae for H2 of Heitler-London for a such divergent term. Then I realized that the Pauli repulsion may only promote the electrons to the empty orbitals, resulting in a FINITE energy increase as r->0. I feel that the exponent 12 is chosen to override the 1/r^6 divergence in r=0 and reduce rapidly the potential to the physically sounded 1/r^6 as r increases. 151.29.78.113 (talk) 20:16, 27 April 2024 (UTC)
replies: text: I removed the incorrect material claiming the 12 was related to Pauli repulsion. Johnjbarton (talk) 17:56, 29 April 2024 (UTC)

text: I change the link to point to Exchange interaction. Johnjbarton (talk) 02:07, 28 April 2024 (UTC)
thread_title:  Pauli repulsion 

message: * The intro here is too long and does not summarized the article. 
* LJ fluids (fictitious fluids with properties caused by LJ potentia) should be grouped in separate section.
* No secondary refs for basic LJ concepts.
* Too many primary refs without secondary refs.
* editorial comments such as "frequently" "extensively" are not referenced.
Johnjbarton (talk) 02:13, 28 April 2024 (UTC)
replies: text: The article fails to explain that 1) the LJ potential began as a model for noble gases (atoms), 2) the repulsive term is heuristic: it was fit to data. Johnjbarton (talk) 02:55, 28 April 2024 (UTC)
replies: text: Thanks for the prompt answer and the accurate reading of the article. The point that hurts a non-expert is that he immediately notes the strong divergence and thinks that the exponent 12 is needed for this; I feel that good results require a good fit only from (about) r0 outward ... I expect that someone has read somewhere this, but finding an explicit statement seems as difficult as to find explicitly 2*375=750. In statistical mechanics the teachers often say that int V exp(-V/kT) dx3 has little importance where V is very large and positive, but this is rarely written in the books pietro151.29.78.113 (talk) 05:13, 28 April 2024 (UTC)

text: Maybe add/borrow from https://doi.org/10.1021/acs.jctc.4c00135, which looks like a good overview. Ldm1954 (talk) 23:10, 28 April 2024 (UTC)
replies: text: @Ldm1954 thanks but I don't have access to the full article. Johnjbarton (talk) 00:47, 29 April 2024 (UTC)
replies: text: I have been able to add that ref now, thanks.  I'll add a short history section as well. Johnjbarton (talk) 17:57, 29 April 2024 (UTC)
thread_title:  Needs work.