HNCO

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Species data

Common Formula	HNCO
Stoichiometric Formula	CHNO
Name	Isocyanic acid
Mass	43.00581 a.m.u
Charge	0
CAS
Inchi	InChI=1S/CHNO/c2-1-3/h2H
InchiKey	OWIKHYCFFJSOEH-UHFFFAOYSA-N
State	Ground State

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KIDA HNCO

ISM Abundance

log₁₀ Abundance	Reference	Source Name	Source Type	Link

Polarizability

No data

Dipole moment

No data

Enthalpy of formation

Evaluation	T (K)	Value (kJ.mol^-1)	Method	Origin	Reference
	0	-119.05 ±0.37	Reviews and Evaluations	Database : Burcat
	298	-118.6 ±0.37	Reviews and Evaluations	Database : Burcat

T (K): 0 Value (kJ.mol^-1) : -119.05 ±0.37 Method: Reviews and Evaluations Origin: Other database Reference:
T (K): 298 Value (kJ.mol^-1) : -118.6 ±0.37 Method: Reviews and Evaluations Origin: Other database Reference:

Desorption energy

Evaluation	E_mean (K)	E_min (K)	E_max (K)	Pre-exponential factor (s^-1)	Order factor	Method	Origin	Reference	Type of surface	Description
	4400 ±1320	0	0	0.00E+0	1	Calculations	Bibliography	Wakelam, V. et al. ;2017;ArXiv e-prints;,	H2O	To estimate the unknown binding energies (for most of the radicals for example), we have developed a model founded on the stabilization energy of the complex between the various species and one water molecule. Then, we assume that the binding energy of the species with ASW is proportional to the energy of interaction between this species and one water molecule. To determine the proportionality coefficients, we fit the dependency of the experimental binding energies versus the calculated energies of the complexes for 16 stable molecules. Uncertainties in ED is estimated to be 30%. The preexponential factor is to be computed using the Hasegawa et al. (1992) approximation.
	2800	0	0	1.28E+12	0	Measurements	Bibliography	Quan, D. et al. ;2010;Astrophysical Journal;725,2101-2109	H2O	Pre-exponential factor is computed using Hasegawa et al. (1992)
	2850	0	0	0.00E+0	1	Estimation	Database : OSU		H2O	This binding energy was listed in the original OSU gas-grain code from Eric Herbst group in 2006. Energy of OCN+H The pre-exponential factor is not given. It can be computed using the formula given in Hasegawa et al. (1992).

E_mean (K): 4400 ±1320 E _min (K): 0 E _max (K): 0 Pre-exponential factor (s^-1): 0.00E+0 Method: Calculations Origin: Bibliography Reference: Wakelam, V. et al. ;2017;ArXiv e-prints;, Type of surface: H2O Description: To estimate the unknown binding energies (for most of the radicals for example), we have developed a model founded on the stabilization energy of the complex between the various species and one water molecule. Then, we assume that the binding energy of the species with ASW is proportional to the energy of interaction between this species and one water molecule. To determine the proportionality coefficients, we fit the dependency of the experimental binding energies versus the calculated energies of the complexes for 16 stable molecules. Uncertainties in ED is estimated to be 30%. The preexponential factor is to be computed using the Hasegawa et al. (1992) approximation. Evaluation:
E_mean (K): 2800 E _min (K): 0 E _max (K): 0 Pre-exponential factor (s^-1): 1.28E+12 Method: Measurements Origin: Bibliography Reference: Quan, D. et al. ;2010;Astrophysical Journal;725,2101-2109 Type of surface: H2O Description: Pre-exponential factor is computed using Hasegawa et al. (1992) Evaluation:
E_mean (K): 2850 E _min (K): 0 E _max (K): 0 Pre-exponential factor (s^-1): 0.00E+0 Method: Estimation Origin: Other database Reference: Type of surface: H2O Description: This binding energy was listed in the original OSU gas-grain code from Eric Herbst group in 2006. Energy of OCN+H The pre-exponential factor is not given. It can be computed using the formula given in Hasegawa et al. (1992). Evaluation:

Diffusion energy

Evaluation	E (K)	Pre-exponential factor (cm² s^-1)	Method	Origin	Reference	Substrate	Type of diffusion	Description
	2946.8	8.10E-4	Measurements	Bibliography	Mispelaer, F. et al. ;2013;Astronomy & Astrophysics;555, A13	H2O ice / Amorphous	surface	These data have been obtained by fitting experimental diffusion rates. The diffusion rates (in cm2s-1) as a function of temperature are listed in Table 3 of Mispelear et al. (2013) and are the following between1.1e-15 and 5e-13 for HNCO (for temperatures between 130 and 140 K).

E (K): 2946.8 Pre-exponential factor (cm² s^-1): 8.10E-4 Method: Measurements Origin: Bibliography Reference: Mispelaer, F. et al. ;2013;Astronomy & Astrophysics;555, A13 Substrate: H2O ice / Amorphous Type of diffusion: surface Description: These data have been obtained by fitting experimental diffusion rates. The diffusion rates (in cm2s-1) as a function of temperature are listed in Table 3 of Mispelear et al. (2013) and are the following between1.1e-15 and 5e-13 for HNCO (for temperatures between 130 and 140 K). Evaluation: