Selected ATcT [1, 2] enthalpy of formation based on version 1.122b of the Thermochemical Network [3]This version of ATcT results was generated from an expansion of version 1.122 [4][5] to include the best possible isomerization of HCN and HNC [6]. 

 
Representative Geometry of [I2] (g)  
spin ON spin OFF  
Top contributors to the provenance of Δ_{f}H° of [I2] (g)The 1 contributors listed below account for 95.9% of the provenance of Δ_{f}H° of [I2] (g).Please note: The list is limited to 20 most important contributors or, if less, a number sufficient to account for 90% of the provenance. The Reference acts as a further link to the relevant references and notes for the measurement. The Measured Quantity is normaly given in the original units; in cases where we have reinterpreted the original measurement, the listed value may differ from that given by the authors. The quoted uncertainty is the a priori uncertainty used as input when constructing the initial Thermochemical Network, and corresponds either to the value proposed by the original authors or to our estimate; if an additional multiplier is given in parentheses immediately after the prior uncertainty, it corresponds to the factor by which the prior uncertainty needed to be multiplied during the ATcT analysis in order to make that particular measurement consistent with the prevailing knowledge contained in the Thermochemical Network.  

Influence Coefficient  TN ID  Reaction  Measured Quantity  Reference 

0.959  869.1  [I2] (g) → I2 (g)  Δ_{r}H°(0 K) = 2.524 ± 0.005 eV  Zanni 1997 
0.012  870.1  I (g) + I2 (g) → [I2] (g) + I (g)  Δ_{r}H°(0 K) = 0.49 ± 0.03 (×1.477) eV  Chupka 1971b 
0.009  872.1  [I2] (g) → I (g) + I (g)  Δ_{r}H°(0 K) = 1.02 ± 0.05 eV  Baede 1973 
0.009  869.3  [I2] (g) → I2 (g)  Δ_{r}H°(0 K) = 2.55 ± 0.05 eV  Baede 1972 
0.004  871.1  Br (g) + I2 (g) → [I2] (g) + Br (g)  Δ_{r}H°(0 K) = 0.77 ± 0.03 (×2.327) eV  Chupka 1971b 
0.002  869.4  [I2] (g) → I2 (g)  Δ_{r}H°(0 K) = 2.52 ± 0.10 eV  Baede 1972, Baede 1973 
0.000  870.2  I (g) + I2 (g) → [I2] (g) + I (g)  Δ_{r}H°(0 K) = 0.59 ± 0.20 eV  Hughes 1973 
0.000  871.2  Br (g) + I2 (g) → [I2] (g) + Br (g)  Δ_{r}H°(0 K) = 1.00 ± 0.20 eV  Hughes 1973 
0.000  869.2  [I2] (g) → I2 (g)  Δ_{r}H°(0 K) = 2.33 ± 0.25 eV  Ayala 1981, est unc 
1 
B. Ruscic, R. E. Pinzon, M. L. Morton, G. von Laszewski, S. Bittner, S. G. Nijsure, K. A. Amin, M. Minkoff, and A. F. Wagner, Introduction to Active Thermochemical Tables: Several "Key" Enthalpies of Formation Revisited. J. Phys. Chem. A 108, 99799997 (2004) [DOI: 10.1021/jp047912y] 

2 
B. Ruscic, R. E. Pinzon, G. von Laszewski, D. Kodeboyina, A. Burcat, D. Leahy, D. Montoya, and A. F. Wagner, Active Thermochemical Tables: Thermochemistry for the 21^{st} Century. J. Phys. Conf. Ser. 16, 561570 (2005) [DOI: 10.1088/17426596/16/1/078] 

3 
B. Ruscic and D. H. Bross, Active Thermochemical Tables (ATcT) values based on ver. 1.122b of the Thermochemical Network (2016); available at ATcT.anl.gov 

4 
B. Ruscic, Active Thermochemical Tables: Sequential Bond Dissociation Enthalpies of Methane, Ethane, and Methanol and the Related Thermochemistry. J. Phys. Chem. A 119, 78107837 (2015) [DOI: 10.1021/acs.jpca.5b01346] 

5 
S. J. Klippenstein, L. B. Harding, and B. Ruscic, Ab initio Computations and Active Thermochemical Tables Hand in Hand: Heats of Formation of Core Combustion Species. J. Phys. Chem. A 121, 65806602 (2017) [DOI: 10.1021/acs.jpca.7b05945] 

6 
T. L. Nguyen, J. H. Baraban, B. Ruscic, and J. F. Stanton, On the HCN – HNC Energy Difference. J. Phys. Chem. A 119, 1092910934 (2015) [DOI: 10.1021/acs.jpca.5b08406] 

7 
B. Ruscic, Uncertainty Quantification in Thermochemistry, Benchmarking Electronic Structure Computations, and Active Thermochemical Tables. Int. J. Quantum Chem. 114, 10971101 (2014) [DOI: 10.1002/qua.24605] 