A tessellationless integration grid for the polarizable continuum model reaction field

2004 ◽  
Vol 25 (12) ◽  
pp. 1532-1541 ◽  
Author(s):  
Christian Silvio Pomelli
Keyword(s):  
Continuum Model ◽  
Polarizable Continuum Model ◽  
Model Reaction ◽  
Reaction Field ◽  
Polarizable Continuum

Solvent and temperature effects on the tautomerization of a carbonitrile molecule: A conductor-like polarizable continuum model (CPCM) study

2021 ◽  
Vol 20 (1) ◽  
pp. 59-68
Author(s):  
Zohreh Khanjari ◽  
Bita Mohtat ◽  
Reza Ghiasi ◽  
Hoorieh Djahaniani ◽  
Farahnaz Kargar Behbahani
Keyword(s):  
Gas Phase ◽  
Solvent Effects ◽  
Continuum Model ◽  
Solvent Polarity ◽  
Polarizable Continuum Model ◽  
Dielectric Constants ◽  
Frontier Orbitals ◽  
Reaction Field ◽  
Polarizable Continuum ◽  
Homo Lumo

This research examined the effects of solvent polarity and temperature on the tautomerization of a carbonitrile molecule at CAM-B3LYP/6-311G (d,p) level of theory. The selected solvents were n-hexane, diethyl ether, pyridine, ethanol, methanol, and water. The solvent effects were examined by the self-consistent reaction field theory (SCRF) based on conductor-like polarizable continuum model (CPCM). The solvent effects were explored on the energy barrier, frontier orbitals energies, and HOMO-LUMO gap. Dependencies of thermodynamic parameters (ΔG and ΔH) on the dielectric constants of solvents were also tested. Specifically, the temperature dependencies of the thermodynamics parameters were studied within 100–1000 K range. The rate constant of the tautomerism reaction was computed from 300 to 1200 K, in the gas phase.

SOLVENT EFFECTS ON THE DISPERSION OF LINEAR POLARIZABILITY AND FIRST HYPERPOLARIZABILITY OF PARA-NITROANILINE USING POLARIZABLE CONTINUUM MODEL

2009 ◽  
Vol 18 (01) ◽  
pp. 85-97 ◽  
Author(s):  
DIKSHA MAKWANI ◽  
R. VIJAYA
Keyword(s):  
Dielectric Constant ◽  
Excitation Energy ◽  
Continuum Model ◽  
Solvent Molecule ◽  
Polarizable Continuum Model ◽  
First Hyperpolarizability ◽  
Excitation Energies ◽  
Frequency Dependent ◽  
Reaction Field ◽  
Polarizable Continuum

The results of ab-initio calculation of frequency dependent linear polarizability α and first hyperpolarizability β of para-nitroaniline (p-NA) in the presence of different solvents are presented using polarizable continuum model (PCM). Geometry of p-NA in different solvents was optimized using HF/6-31 + G(d,p). Both static and frequency dependent α and β initially increase with an increase in the dielectric constant of the solvent used with p-NA, but subsequently attain an almost constant value. With solvents of higher dielectric constant, the value of static β is more compared to the β value at 1.17 eV but less than the value at 2 eV. Even though the existence of the solvent effect is confirmed from the results, the β values calculated at both 1.17 eV and 2 eV do not show any linear relationship with the dielectric constant and the reaction field factor of the solvents. The first excitation energies of both α and β of p-NA are considerably different in the presence of solvents as compared to their values in the gas phase, but the change with dielectric constant of the solvent is not very significant. The effect of hydrogen bonding between the solute and the solvent molecule on the first excitation energy of hyperpolarizability has been included using the explicit solvent method. The values of the first excitation energy calculated using the explicit method are lower than those obtained by the implicit method.

scholarly journals Propiedades catalíticas de grafeno dopado con metales de transición

2018 ◽  
Vol 23 (2) ◽  
Author(s):  
Víctor Aramburu ◽  
María López ◽  
Héctor Fasoli
Keyword(s):  
Continuum Model ◽  
Polarizable Continuum Model ◽  
Reaction Field ◽  
Self Consistent ◽  
Polarizable Continuum

RESUMEN En este trabajo se realiza un estudio basado en la Teoría del Funcional de la Densidad de láminas de grafeno dopadas con Fe, Co y Ni. Se adopta el funcional PBE1PBE y los pseudopotenciales LANL2DZ para los átomos metálicos y las bases 6-31G++(d) para los átomos de carbono. Se analizan tres sistemas formados por la sustitución de un átomo carbono por uno de Fe, Co y Ni, respectivamente. Se estudiaron las propiedades energéticas, electrónicas y la reactividad química, haciendo una comparación sistemática con una lámina de grafeno puro. Para simular la presencia del solvente en los sistemas de estudio se empleó el modelo SCRF=PCM (Self-Consistent Reaction Field=Polarizable Continuum Model). Asimismo, se determinaron las propiedades catalíticas de los sistemas frente a la adsorción de O2. Los resultados indican que la presencia del heteroátomos metálicos y agua como solvente modifica la reactividad química y la adsorción de dioxígeno, lo que podría ser determinante en las propiedades catalíticas del grafeno dopado. La lámina de grafeno dopado con níquel resulta la más reactiva y la que presenta energía más favorable frente a la adsorción de oxígeno.

THEORETICAL CALCULATION OF pKb VALUES FOR ANILINES AND SULFONAMIDE DRUGS IN AQUEOUS SOLUTION

2012 ◽  
Vol 11 (02) ◽  
pp. 283-295 ◽  
Author(s):  
BAHRAM GHALAMI-CHOOBAR ◽  
ALI GHIAMI-SHOMAMI ◽  
PARIA NIKPARSA
Keyword(s):  
Gas Phase ◽  
Continuum Model ◽  
Correlation Equation ◽  
Polarizable Continuum Model ◽  
Free Energies ◽  
Pcm Model ◽  
Solvation Models ◽  
Polarizable Continuum ◽  
Better Than ◽  
Good Agreement

In this work, calculations of p K b values have been performed for aniline and its substituted derivatives and sulfonamide drugs by using Gaussian 98 software package. Gas-phase energies were calculated with HF /6-31 G ** and B3LYP /6-31 G ** levels of theory. Free energies of solvation have been computed using the polarizable continuum model (PCM), conductor-like polarizable continuum model (CPCM) and the integral equation formalism-polarizable continuum model (IEFPCM) at the same levels which have been used for geometry determination in the gas-phase. The results show that the calculated p K b values using the B3LYP /6-31 G ** are better than those using the corresponding HF /6-31 G **. At first, the correlation equation was found to determine the p K b values of the investigated anilines. Then, this correlation equation was used to calculate the p K b values of the sulfonamide drugs. The results obtained indicate that the PCM model is a suitable solvation model for calculating p K b values in comparison to the other solvation models. For the investigated compounds a good agreement between the experimental and the calculated p K b values was also observed.

A new discretization for the polarizable continuum model within the domain decomposition paradigm

2016 ◽  
Vol 144 (5) ◽  
pp. 054101 ◽  
Author(s):  
Benjamin Stamm ◽  
Eric Cancès ◽  
Filippo Lipparini ◽  
Yvon Maday
Keyword(s):  
Domain Decomposition ◽  
Continuum Model ◽  
Polarizable Continuum Model ◽  
Polarizable Continuum
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