Related Experiment Video
Updated: Jul 18, 2026
08:44
Assembly and Characterization of Polyelectrolyte Complex Micelles
Published on: March 2, 2020
Coupling quantum Monte Carlo to a nonlinear polarizable continuum model for spherical solutes
Claudio Amovilli1, Claudia Filippi, Franca Maria Floris
1Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Risorgimento 35, I-56126 Pisa, Italy. amovilli@dcci.unipi.it
The Journal of Physical Chemistry. B
|December 22, 2006
Summary
This study presents a new analytical model for calculating solvation free energy, accounting for solvent effects on solutes. The method accurately predicts the hydration of atomic ions using quantum Monte Carlo simulations.
Area of Science:
- Computational Chemistry
- Physical Chemistry
- Theoretical Chemistry
Background:
- Solvation free energy is crucial for understanding chemical processes in solution.
- Existing models often simplify solvent interactions, limiting accuracy.
- Accurate modeling requires incorporating solute electronic density and solvent dielectric properties.
Purpose of the Study:
- To derive an analytical expression for the polarization contribution to solvation free energy.
- To develop an effective potential representing solvent effects on solutes.
- To validate the model by applying it to the hydration of atomic ions.
Main Methods:
- Utilized the nonlinear dielectric response model of Sandberg and Edholm.
- Incorporated solvent inhomogeneity using a smooth switching function.
- Employed quantum Monte Carlo techniques for solute treatment.
- Applied functional analysis to derive an explicit local potential.
Main Results:
- Derived an analytical expression for polarization contribution to solvation free energy.
- Obtained an effective local potential for solvent effects.
- Achieved very good agreement between calculated and experimental hydration free energies for atomic ions.
Conclusions:
- The developed model provides an accurate method for calculating solvation free energy.
- The effective potential is suitable for integration with quantum mechanical methods.
- The approach demonstrates high predictive power for ionic hydration.
Related Concept Videos
01:29Potential Due to a Polarized Object
A neutral atom consists of a positively charged nucleus surrounded by a negatively charged electron cloud. When placed in an external electric field, the external electric force pulls the electrons and nucleus apart, opposite to the intrinsic attraction between the nucleus and the electrons. The opposing forces balance each other with a slight shift between the center of masses of the nucleus and the electron cloud, resulting in a polarized atom. On the other hand, a few molecules, like water,...
01:27¹H NMR: Long-Range Coupling
The coupling interactions of nuclei across four or more bonds are usually weak, with J values less than 1 Hz. While these are usually not observed in spectra, the presence of multiple bonds along the coupling pathway can result in observable long-range coupling.
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene π orbitals.
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene π orbitals.
01:29Mechanistic Models: Compartment Models in Algorithms for Numerical Problem Solving
Mechanistic models play a crucial role in algorithms for numerical problem-solving, particularly in nonlinear mixed effects modeling (NMEM). These models aim to minimize specific objective functions by evaluating various parameter estimates, leading to the development of systematic algorithms. In some cases, linearization techniques approximate the model using linear equations.
In individual population analyses, different algorithms are employed, such as Cauchy's method, which uses a...
In individual population analyses, different algorithms are employed, such as Cauchy's method, which uses a...
01:23Equilibrium Conditions for a Particle
When an object is in equilibrium, it is either at rest or moving with a constant velocity. There are two types of equilibrium: static and dynamic. Static equilibrium occurs when an object is at rest, while dynamic equilibrium occurs when an object is moving with a constant velocity. In both cases, there must be a balance of forces acting on the object.
To understand the concept of equilibrium, let us first consider the forces acting on an object. When different forces act on an object, they can...
To understand the concept of equilibrium, let us first consider the forces acting on an object. When different forces act on an object, they can...
01:34Fluid Mosaic Model
The fluid mosaic model was first proposed as a visual representation of research observations. The model comprises the composition and dynamics of membranes and serves as a foundation for future membrane-related studies. The model depicts the structure of the plasma membrane with a variety of components, which include phospholipids, proteins, and carbohydrates. These integral molecules are loosely bound, defining the cell’s border and providing fluidity for optimal function.LipidsThe most...
01:19Fluid Mosaic Model
Scientists identified the plasma membrane in the 1890s and its principal chemical components (lipids and proteins) by 1915. The model for plasma membrane structure, proposed in 1935 by Hugh Davson and James Danielli, was the first model to be widely accepted in the scientific community. The model was based on the plasma membrane's "railroad track" appearance in early electron micrographs. Davson and Danielli theorized that the plasma membrane's structure resembled a sandwich with the analogy of...