search

ReactionMechanismGenerator / RMG-database

The database of chemical parameters used with Reaction Mechanism Generator
http://rmg.mit.edu/database/
95 stars 139 forks source link

O=C=C=C=O thermo #476

Open davidfarinajr opened 3 years ago

davidfarinajr commented 3 years ago

Thermo group additivity estimation for O=C=C=C=O (https://rmg.mit.edu/database/thermo/molecule/1%20O%20u0%20p2%20c0%20%7B2,D%7D%0A2%20C%20u0%20p0%20c0%20%7B1,D%7D%20%7B3,D%7D%0A3%20C%20u0%20p0%20c0%20%7B2,D%7D%20%7B4,D%7D%0A4%20C%20u0%20p0%20c0%20%7B3,D%7D%20%7B5,D%7D%0A5%20O%20u0%20p2%20c0%20%7B4,D%7D%0A)

is significantly off from ATcT (https://atct.anl.gov/Thermochemical%20Data/version%201.122p/species/?species_number=279).

H298 from GAV is +34 kcal/mol and ATcT H298 is -22 kcal/mol.

We can add O=C=C=C=O to a thermo library (perhaps primaryThermoLibrary), but we should look into thermo groups more closely to see if this error is systematic for these types of molecules

davidfarinajr commented 3 years ago
smiles h298_gav_master s298_gav_master h298_gav_pr s298_gav_pr h298_G4 s298_G4
O=C=C=C=O 34.2 4.62 34.2 4.62 -22.38 65.8
O=C=C=C=C=O 68.4 10.62 35.26 75.1 50.42 73.41
O=C=C=C=C=C=O 102.6 16.62 69.46 81 43.5 70.3

units are kcal/mol, cal/mol/k

davidfarinajr commented 3 years ago

PR is thermo groups using this PR branch https://github.com/ReactionMechanismGenerator/RMG-database/pull/473 which adds a Cdd-(Cdd-O2d)Cds group

davidfarinajr commented 3 years ago

Seems to be a systematic issue with O=C=C...C=O molecules. Both the master and PR branches are quite poor at O=C=C=C=O so that could be added to thermo library, but the PR branch looks like it's better for the other molecules, especially for entropy, than the master branch.

rwest commented 2 years ago

Is this issue fully addressed by #478 and #473 and other thermo group improvements? can it be closed?