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Error in thermo estimation for phenoxy radical #287
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Thanks @ssommari. |
Maybe it's Off Topic, but more oxygenated species (alkyl peroxy radicals) seem wrong. Enthalpies (kcal/mol:) Blanksby et al J. Am. Chem. Soc. 2001, 123, 9585-9596 Just so that you know. |
Hey All, I have tried to enter Thermo through the website but haven't had any luck. It I have hundreds of Thermo values from literature that have been collected over the years in the Ellison lab. ( Mostly enthalpies and fewer heat capacities) I have looked through the current RMG Thermo database and the paper recently published by Franklin and still have plenty of new good Thermo to add to RMG database. It's just a matter of the best way to get into database. I would love to do contribute this to the RMG database. I know Connie has been very busy and has lots of tasks but maybe we can figure out... if the website is still the best way to Thermo into RMG. Thoughts? Dr. AnGayle K.Vasiliou |
Hi @avasilio - what format do you have the data in? |
On the topic of the wrong enthalpy of formation for phenoxy radical: Despite the threatening warning messages (eg This also has nothing to do with the aromaticity perception algorithm, which worked perfectly in this case. I believe that RMG is only able to match the generic COJ HBI entry because nothing more accurate could be found in the radical tree that matches the atomic environment of the oxygen radical in phenoxy. In other words: @ssommari Bottom line: this is a data problem, rather than an algorithmic one. Once we have a CbOJ entry, it should be fine. Not surprisingly, checking rmg.mit.edu also shows the error. |
I downloaded recently (less than a mont ago) RMG to get thermodynamics data.
Phenoxy radical is wrong.
I am not sure if your method uses Benson group additivity or Bozzelli corrections for radicals.
(SPECIES, Method, H, S , Cp 300, 400, 500, 600, 1000, 1500)
PHENOXY THERM 12.10, 76.47, 22.82, 29.76, 35.65, 40.40, 47.41, 52.15, 59.35
PHENOXY RMG 29.66, 73.71, 23.42, 30.70, 36.71, 41.44,48.24, 52.76, 59.57
PHENOL BOTH -22.30, 75.17, 24.40, 32.00, 38.32, 43.33, 50.62, 55.56, 63.16
H 52.11, 27.42, 3.52, 3.53, 3.55, 3.58, 3.61, 3.72, 3.90
If you take the delta H @298 for PHENOXY + H = PHENOL
RMG bond dissociation energy = ~104
THERM bond dissociation energy = ~86.5
In the common tables for B.D.E., 104 is the typical number for an ALKOXY radical (CCOJ), while VINOXY radycal (C=COJ) is on the order of 85. (which is the typical number for resonant system)
It seems to me that RMG cannot find the proper number of resonant radical: the RMG.log states "The number of resonance isomers is 0"
I attach my input and my output to see if you can reproduce my issue.
Further informations:
The adjacency list are taken from your online smiles to adjacency.
Using an adjacency list which use single-double bonds in the aromatic ring doesn't change anything.
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