Timeline for What is the biggest known difference between rₑ and r₀?
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13 events
| when toggle format | what | by | license | comment | |
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| Sep 22, 2019 at 21:33 | comment | added | user1420303 | Good question +1. @porphyrin I think that it is not the same that anharmonicity. I would separate the contributions due the potential as $\mu(V)$ (with $\mu=r(V)-r_e$) into the sum of symmetric and assymetric contributions. The expected value of the symmetric part will be 0, so only the assymetric part contributes to $r_0-r_e$ | |
| Sep 11, 2019 at 18:08 | answer | added | jheindel | timeline score: 3 | |
| Sep 2, 2019 at 12:15 | history | edited | Martin - マーチン♦ | CC BY-SA 4.0 |
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| Aug 31, 2019 at 16:35 | comment | added | user1271772 | @porphyrin: also please see footnode 6 on the same page! | |
| Aug 31, 2019 at 16:08 | comment | added | user1271772 | @porphyrin: Actually you're wrong and you're right at the same time. You were right originally by mentioning the ratio $D_e/\omega_e$ and wrong about $\omega_ex_e$ not being related. See Eq. 3.16 !! scienide2.uwaterloo.ca/~rleroy/c209/Primer.pdf. | |
| Aug 31, 2019 at 15:11 | comment | added | porphyrin | The reason $x_e\omega_e$ is big for hydrogen is because the frequency is big so this product is misleading. A low frequency and a big dissociation energy seems to mean a big anharmonicity in the bond. For example PbBr, or SiTe. The question was about calculating the difference between $x_e$ and $x_0$ the latter I took to be the average bond length $\int \psi^*_0\psi_0rdr/\int\psi^*_0\psi_0$ | |
| Aug 30, 2019 at 21:41 | comment | added | user1271772 | @porphyrin: Where do you get that from? So you are saying the anharmonicity $\omega_e \chi_e$ does not enter at all? To maximize $D_e/\omega_e$ we just have to find the heaviest molecule (meaning small $\omega_e$) that is bound strongly (large $D_e$). | |
| Aug 27, 2019 at 17:42 | comment | added | porphyrin | Keeping things simple, if the average bond length ($r_0$) for $n=0$ is calculated for a Morse potential then the largest deviation from $r_e$ seems to be proportional to the ratio $ D_e / \omega_e$. | |
| Aug 24, 2019 at 23:05 | comment | added | user1271772 | The largest anharmonic constant $\omega_e\chi_e$ in the CRC book for a diatomic is 121.34 cm$^{-1}$ (for H2). | |
| Aug 24, 2019 at 18:00 | history | tweeted | twitter.com/StackChemistry/status/1165322898942414849 | ||
| Aug 24, 2019 at 11:47 | comment | added | user1271772 | @porphyrin: I thought of asking that too, but as a separate question because I don't think it is guaranteed to have the same answer. Some bonds have a double-well potential, whose solution to the Schrödinger equation (eigenfunction/wavefunction) is not so simple anymore. Likewise in polyatomics the picture is much more complicated than in this diagram. | |
| Aug 24, 2019 at 11:35 | comment | added | porphyrin | I think what you are asking is, in effect, 'what is the most anharmonic bond?' as this will give the greatest ratio of lengths. | |
| Aug 24, 2019 at 6:14 | history | asked | user1271772 | CC BY-SA 4.0 |