Modelling Macroscopic Properties of Organic Species on the Basis of Quantum Chemical Analysis (on an Example of Inhibiting Efficiency of Ureides and Acetylides against Corrosion)

2014 ◽  
Vol 225 ◽  
pp. 7-12
Author(s):  
Georgy S. Beloglazov ◽  
Andrei A. Sikachina ◽  
Sergei M. Beloglazov
Keyword(s):  
Experimental Data ◽  
Dipole Moment ◽  
Quantum Chemical ◽  
Quantum Chemical Analysis ◽  
Chemical Methods ◽  
Organic Species ◽  
Quantum Chemical Methods ◽  
Homo And Lumo ◽  
Inhibitive Action ◽  
Quantum Chemical Data

The experimental data on efficiencies of a series of 7 ureides and 5 acetylides as inhibitors (IN) of corrosion of mild steel in Postgate B media compared to quantum chemical data; the following descriptors found to be essential to describe the inhibitive properties under given conditions: energies of the boundary molecular orbitals (HOMO and LUMO) and dipole moment. The inhibitive properties of the chosen ureides under given conditions are based on electron donating rather than accepting properties of their molecules. PM/3 method was found to be preferable compared to other quantum chemical methods used (i.e., MNDO, AM/1), and even non-empiricab initiomethods because it is found to be more helpful in explaining the mechanism of inhibitive action of organic species.

scholarly journals Energetic Degeneracy and Electronic Structures of Germanium Trimers Doped with Titanium

2020 ◽  
Author(s):  
Le Nhan Pham ◽  
Salvy P. Russo
Keyword(s):  
Experimental Data ◽  
Excited States ◽  
Electronic Structures ◽  
Quantum Chemical ◽  
Electronic Transitions ◽  
Chemical Methods ◽  
Quantum Chemical Methods ◽  
Experimental Group ◽  
Comparison With Experimental Data

Several quantum chemical methods including CASSCF/CASPT2, CCSD(T)-F12, and DFT were used to study electronic structures and excited states of germanium trimers singly doped with titanium. All necessary parameters and calculations process are reported in the text. The conclusion on electronic transitions causing anion photoelectron bands was made by analysis of electronic structures and comparison with experimental data (reported by an experimental group).

Trimethylammoniodiformylmethylide: Structure and charge distribution

1980 ◽  
Vol 45 (1) ◽  
pp. 80-91 ◽  
Author(s):  
Vladimír Král ◽  
Zdeněk Arnold
Keyword(s):  
Dipole Moment ◽  
Total Energy ◽  
Ab Initio ◽  
Charge Distribution ◽  
Quantum Chemical ◽  
Energy Minimum ◽  
Chemical Methods ◽  
Quantum Chemical Methods ◽  
Total Energy Minimum

Geometric arrangement of trimethylammoniodiformylmethylide (I) and charge distribution in this compound were calculated by quantum chemical methods (EHT, CNDO/2, INDO, PCILO, MINDO/2, ab initio). Total energy minimum was found for the arrangement If. The experimentally found dipole moment agrees very well with that calculated for this conformation.

Spin-state energetics of metallocenes: How do best wave function and density functional theory results compare with the experimental data?

2021 ◽  
Vol 23 (1) ◽  
pp. 151-172
Author(s):  
Gabriela Drabik ◽  
Janusz Szklarzewicz ◽  
Mariusz Radoń
Keyword(s):  
Experimental Data ◽  
Density Functional Theory ◽  
Wave Function ◽  
Spin State ◽  
Quantum Chemical ◽  
Density Functional ◽  
Chemical Methods ◽  
Functional Theory ◽  
Quantum Chemical Methods

Benchmarking quantum-chemical methods against experiment-derived spin-state energetics of metallocenes.

scholarly journals Monomolecular Films of Organic Diacyl Diperoxides on the Interface of the Phases Water–Air

2021 ◽  
Vol 15 (4) ◽  
pp. 536-542
Author(s):  
Volodymyr Dutka ◽  
◽  
Olena Aksimentyeva ◽  
Yaroslav Kovalskyi ◽  
Natalya Oshchapovska ◽  
...  
Keyword(s):  
Experimental Data ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Phase Interface ◽  
Chemical Methods ◽  
Conformational States ◽  
Quantum Chemical Methods ◽  
Monomolecular Films

Monomolecular films of diacyl diperoxides at the water–air phase interface have been studied. Their behaviour is influenced by the structure of the molecule and the solvent. The numerical values of the areas of molecules that are extrapolated to zero pressure are different, which indicates a different conformation of the molecules in the monolayer. The conformational states of diperoxides were calculated by quantum chemical methods. Experimental data and quantum chemical calculations are consistent with each other.

scholarly journals Atmospheric Cluster Dynamics Code: a flexible method for solution of the birth-death equations

2011 ◽  
Vol 11 (9) ◽  
pp. 25263-25295 ◽  
Author(s):  
M. J. McGrath ◽  
T. Olenius ◽  
I. K. Ortega ◽  
V. Loukonen ◽  
P. Paasonen ◽  
...  
Keyword(s):  
Quantum Chemical ◽  
Rate Coefficients ◽  
Free Energies ◽  
Chemical Methods ◽  
Quantum Chemical Methods ◽  
Initial Cluster ◽  
Sticking Probabilities ◽  
Quantum Chemical Data ◽  
Birth Death ◽  
Atmospherically Relevant

Abstract. The Atmospheric Cluster Dynamics Code (ACDC) is presented and explored. This program was created to study the first steps of atmospheric new particle formation by examining the formation of molecular clusters from atmospherically relevant molecules. The program models the cluster kinetics by explicit solution of the birth–death equations, using an efficient computer script for their generation and the MATLAB ode15s routine for their solution. Through the use of evaporation rate coefficients derived from formation free energies calculated by quantum chemical methods for clusters containing dimethylamine or ammonia and sulphuric acid, we have explored the effect of changing various parameters at atmospherically relevant monomer concentrations. We have included in our model clusters with 0–4 base molecules and 0–4 sulfuric acid molecules for which we have commensurable quantum chemical data. The tests demonstrate that large effects can be seen for even small changes in different parameters, due to the non-linearity of the system. In particular, the temperature and sticking probabilities both have a large impact on all clusters, while the boundary effects (allowing clusters to grow to sizes beyond the largest cluster that the code keeps track of, or forbidding such processes), coagulation sink terms, non-monomer collisions, and monomer concentrations can all have significant effects. Removal of coagulation sink terms prevented the system from reaching the steady state when all the initial cluster concentrations were set to the default value of 1 m−3, which is probably an effect caused by studying only relatively small cluster sizes.

scholarly journals Energetic Degeneracy and Electronic Structures of Germanium Trimers Doped with Titanium

2020 ◽  
Author(s):  
Le Nhan Pham ◽  
Salvy P. Russo
Keyword(s):  
Experimental Data ◽  
Excited States ◽  
Electronic Structures ◽  
Quantum Chemical ◽  
Electronic Transitions ◽  
Chemical Methods ◽  
Quantum Chemical Methods ◽  
Experimental Group ◽  
Comparison With Experimental Data

Several quantum chemical methods including CASSCF/CASPT2, CCSD(T)-F12, and DFT were used to study electronic structures and excited states of germanium trimers singly doped with titanium. All necessary parameters and calculations process are reported in the text. The conclusion on electronic transitions causing anion photoelectron bands was made by analysis of electronic structures and comparison with experimental data (reported by an experimental group).

scholarly journals Energetics of LOHC: Structure-Property Relationships from Network of Thermochemical Experiments and in Silico Methods

Hydrogen ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 101-121
Author(s):  
Sergey P. Verevkin ◽  
Vladimir N. Emel’yanenko ◽  
Riko Siewert ◽  
Aleksey A. Pimerzin
Keyword(s):  
In Silico ◽  
Quantum Chemical ◽  
Structure Property ◽  
Chemical Methods ◽  
Key Technology ◽  
Structure Property Relationships ◽  
Quantum Chemical Methods ◽  
Dehydrogenation Reactions ◽  
Storage Technologies ◽  
In Silico Methods

The storage of hydrogen is the key technology for a sustainable future. We developed an in silico procedure, which is based on the combination of experimental and quantum-chemical methods. This method was used to evaluate energetic parameters for hydrogenation/dehydrogenation reactions of various pyrazine derivatives as a seminal liquid organic hydrogen carriers (LOHC), that are involved in the hydrogen storage technologies. With this in silico tool, the tempo of the reliable search for suitable LOHC candidates will accelerate dramatically, leading to the design and development of efficient materials for various niche applications.

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