Progress towards machine learning reaction rate constants

Author(s):  
Evan Komp ◽  
Nida Janulaitis ◽  
Stephanie Valleau

Quantum and classical reaction rate constant calculations come at the cost of exploring potential energy surfaces. Due to the “curse of dimensionality”, their evaluation quickly becomes unfeasible as the system...

1974 ◽  
Vol 52 (2) ◽  
pp. 287-290 ◽  
Author(s):  
Seiichiro Koda

A molecular orbital study within the framework of the CNDO/2 method has been made of the reactions of ground state oxygen atoms with olefins. Calculated excitation energies confirm the existence of a certain correlation between those and the logarithm of the reaction rate constants. The location of minima in the simplified potential energy surfaces computed appear to correspond to the reaction intermediates suggested previously.


1997 ◽  
Vol 119 (2) ◽  
pp. 108-113 ◽  
Author(s):  
D. Y. Goswami ◽  
S. K. Sharma ◽  
G. D. Mathur ◽  
C. K. Jotshi

Solar detoxification technology has shown great promise for treatment of toxic compounds in the ground water and wastewater. However, detailed analysis of the impact of techno-economic parameters on the treatment cost for the detoxification process is lacking in the literature. In this paper, the impact of different process parameters on the treatment cost has been presented and various strategies for reducing the cost of treatment have been discussed. For the processes with the reaction rate constants less than 0.1 min−1, the system economics is very sensitive to the reaction rate constant and the unit reactor cost. However, for the reaction rate constant over 0.1 min−1 the general treatment costs can be reduced mainly by reducing the unit catalyst costs.


Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4803
Author(s):  
Krystian Mistewicz ◽  
Mirosława Kępińska ◽  
Marian Nowak ◽  
Agnieszka Sasiela ◽  
Maciej Zubko ◽  
...  

Piezocatalysis is a novel method that can be applied for degradation of organic pollutants in wastewater. In this paper, ferroelectric nanowires of antimony sulfoiodide (SbSI) have been fabricated using a sonochemical method. Methyl orange (MO) was chosen as a typical pollutant, as it is widely used as a dye in industry. An aqueous solution of MO at a concentration of 30 mg/L containing SbSI nanowires (6 g/L) was subjected to ultrasonic vibration. High degradation efficiency of 99.5% was achieved after an extremely short period of ultrasonic irradiation (40 s). The large reaction rate constant of 0.126(8) s−1 was determined for piezocatalytic MO decomposition. This rate constant is two orders of magnitude larger than values of reaction rate constants reported in the literature for the most efficient piezocatalysts. These promising experimental results have proved a great potential of SbSI nanowires for their application in environmental purification and renewable energy conversion.


Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3478 ◽  
Author(s):  
Hugo G. Machado ◽  
Flávio O. Sanches-Neto ◽  
Nayara D. Coutinho ◽  
Kleber C. Mundim ◽  
Federico Palazzetti ◽  
...  

The Transitivity function, defined in terms of the reciprocal of the apparent activation energy, measures the propensity for a reaction to proceed and can provide a tool for implementing phenomenological kinetic models. Applications to systems which deviate from the Arrhenius law at low temperature encouraged the development of a user-friendly graphical interface for estimating the kinetic and thermodynamic parameters of physical and chemical processes. Here, we document the Transitivity code, written in Python, a free open-source code compatible with Windows, Linux and macOS platforms. Procedures are made available to evaluate the phenomenology of the temperature dependence of rate constants for processes from the Arrhenius and Transitivity plots. Reaction rate constants can be calculated by the traditional Transition-State Theory using a set of one-dimensional tunneling corrections (Bell (1935), Bell (1958), Skodje and Truhlar and, in particular, the deformed ( d -TST) approach). To account for the solvent effect on reaction rate constant, implementation is given of the Kramers and of Collins–Kimball formulations. An input file generator is provided to run various molecular dynamics approaches in CPMD code. Examples are worked out and made available for testing. The novelty of this code is its general scope and particular exploit of d -formulations to cope with non-Arrhenius behavior at low temperatures, a topic which is the focus of recent intense investigations. We expect that this code serves as a quick and practical tool for data documentation from electronic structure calculations: It presents a very intuitive graphical interface which we believe to provide an excellent working tool for researchers and as courseware to teach statistical thermodynamics, thermochemistry, kinetics, and related areas.


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