scholarly journals Fragment-based quantum mechanical methods for periodic systems with Ewald summation and mean image charge convention for long-range electrostatic interactions

2012 ◽  
Vol 14 (21) ◽  
pp. 7821 ◽  
Author(s):  
Peng Zhang ◽  
Donald G. Truhlar ◽  
Jiali Gao
Keyword(s):  
Long Range ◽  
Electrostatic Interactions ◽  
Periodic Systems ◽  
Quantum Mechanical ◽  
Image Charge ◽  
Ewald Summation ◽  
Mechanical Methods

The docking manoeuvre at a drug receptor: a quantum mechanical study of intercalative attack of ethidium and its carboxylated derivative on a DNA fragment

1979 ◽  
Vol 287 (1025) ◽  
pp. 571-604 ◽  
Keyword(s):  
Electrostatic Potential ◽  
Electrostatic Interactions ◽  
Dimensional Space ◽  
Receptor Interaction ◽  
Quantum Mechanical ◽  
Space Vehicles ◽  
Drug Molecule ◽  
Drug Molecules ◽  
Mechanical Methods ◽  
Drug Receptor

Various semi-empirical quantum mechanical methods have been used to investigate the docking manoeuvre of ethidium and of its carboxylated derivative at the (dC-dG) • (dC-dG) receptor. The objective of the work was to determine whether the drug attacks the receptor in a random orientation or is pre-aligned for effective docking. An analogy was made between the interaction and two docking space vehicles. Charge distributions were computed for the intercalative site and the drug molecules; from these distributions it was possible to map, in three-dimensional space, the molecular electrostatic potential surrounding the receptor. Perturbation of the receptor fields by an approaching drug molecule showed field neutralization and a shifting local minimum as docking proceeds. Most of the electrostatic potential surrounding the receptor was shown to be derived from the two ionized phosphate groups. The orientation of the drug molecule was studied in a simplified anionic field constructed to reproduce that of the receptor phosphates. Rotation of ethidium and p -carboxyphenylethidium round the Eulerian axes in this simulated anionic field showed up distinct preferences for orientation of drug molecules in the vicinity of the receptor. Probability distributions for rotational populations demonstrated clearly that the receptor induces an orientation in the approaching ligand. The energy involved in modification of the alignment could be attributed to electrostatic interactions over large separation distances and to induced electron delocalization as the drug approaches closer to the receptor. This partition of the energy was considered further by monitoring electron migration in the drug molecules and analysis of dipole moment fluctuations. Orientation restrictions reflect entropy changes in the association reaction; these are discussed with respect to their importance in determination of reaction kinetics, and in two established models for drug- receptor interaction, namely, the ‘lock and key’ and ‘zipper’ mechanisms.

Handling Electrostatic Interactions in Molecular Simulations: A Systematic Study

2008 ◽  
Vol 73 (4) ◽  
pp. 481-506 ◽  
Author(s):  
Jiří Kolafa ◽  
Filip Moučka ◽  
Ivo Nezbeda
Keyword(s):  
Molecular Dynamics ◽  
Monte Carlo ◽  
Long Range ◽  
Electrostatic Interactions ◽  
Short Range ◽  
Ewald Summation ◽  
Field Methods ◽  
Reaction Field ◽  
Lennard Jones ◽  
Dynamics Simulations

Two qualitatively different models with strong long-range electrostatic interactions, Lennard-Jones diatomics with an embedded dipole moment and TIP4P/2005 water, are considered in extensive Monte Carlo and molecular dynamics simulations to systematically study the differences in results caused by different treatments of the long-range electrostatic interactions. In addition to the standard Ewald summation and reaction field methods, we consider also two variants of short-range approximations. Both thermodynamic and structural properties, and both homogeneous and inhomogeneous phases are considered. It is shown that the accuracy of the short-range approximations with carefully selected parameters may be sufficient for a number of applications; however, in some cases one can encounter accuracy limits or structural or other artifacts.

scholarly journals Interactions between large molecules pose a puzzle for reference quantum mechanical methods

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yasmine S. Al-Hamdani ◽  
Péter R. Nagy ◽  
Andrea Zen ◽  
Dennis Barton ◽  
Mihály Kállay ◽  
...  
Keyword(s):  
Experimental Information ◽  
Quantum Mechanical ◽  
Interaction Energies ◽  
Small Organic Molecules ◽  
Large Molecules ◽  
Reference Information ◽  
Mechanical Methods ◽  
Non Covalent Interactions ◽  
Semi Empirical ◽  
Covalent Interactions

AbstractQuantum-mechanical methods are used for understanding molecular interactions throughout the natural sciences. Quantum diffusion Monte Carlo (DMC) and coupled cluster with single, double, and perturbative triple excitations [CCSD(T)] are state-of-the-art trusted wavefunction methods that have been shown to yield accurate interaction energies for small organic molecules. These methods provide valuable reference information for widely-used semi-empirical and machine learning potentials, especially where experimental information is scarce. However, agreement for systems beyond small molecules is a crucial remaining milestone for cementing the benchmark accuracy of these methods. We show that CCSD(T) and DMC interaction energies are not consistent for a set of polarizable supramolecules. Whilst there is agreement for some of the complexes, in a few key systems disagreements of up to 8 kcal mol−1 remain. These findings thus indicate that more caution is required when aiming at reproducible non-covalent interactions between extended molecules.

scholarly journals A Review on Combination of Ab Initio Molecular Dynamics and NMR Parameters Calculations

2021 ◽  
Vol 22 (9) ◽  
pp. 4378
Author(s):  
Anna Helena Mazurek ◽  
Łukasz Szeleszczuk ◽  
Dariusz Maciej Pisklak
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Small Amplitude ◽  
Ab Initio Molecular Dynamics ◽  
Quantum Mechanical ◽  
Time Step ◽  
Noticeable Effect ◽  
Nmr Parameters ◽  
Mechanical Methods ◽  
Simulation Time

This review focuses on a combination of ab initio molecular dynamics (aiMD) and NMR parameters calculations using quantum mechanical methods. The advantages of such an approach in comparison to the commonly applied computations for the structures optimized at 0 K are presented. This article was designed as a convenient overview of the applied parameters such as the aiMD type, DFT functional, time step, or total simulation time, as well as examples of previously studied systems. From the analysis of the published works describing the applications of such combinations, it was concluded that including fast, small-amplitude motions through aiMD has a noticeable effect on the accuracy of NMR parameters calculations.

scholarly journals New Approach for Correcting Noncovalent Interactions in Semiempirical Quantum Mechanical Methods: The Importance of Multiple-Orientation Sampling

2021 ◽  
Vol 17 (9) ◽  
pp. 5556-5567
Author(s):  
Sergio Pérez-Tabero ◽  
Berta Fernández ◽  
Enrique M. Cabaleiro-Lago ◽  
Emilio Martínez-Núñez ◽  
Saulo A. Vázquez
Keyword(s):  
Noncovalent Interactions ◽  
Quantum Mechanical ◽  
New Approach ◽  
Mechanical Methods

scholarly journals Polarizable embedding for simulating redox potentials of biomolecules

2019 ◽  
Vol 21 (22) ◽  
pp. 11642-11650 ◽  
Author(s):  
Ruslan N. Tazhigulov ◽  
Pradeep Kumar Gurunathan ◽  
Yongbin Kim ◽  
Lyudmila V. Slipchenko ◽  
Ksenia B. Bravaya
Keyword(s):  
Long Range ◽  
Electrostatic Interactions ◽  
Theoretical Description ◽  
Biological Macromolecules ◽  
Classical Approach ◽  
Redox Potentials ◽  
Computational Protocol ◽  
Polarizable Embedding

We present a computational protocol exploiting polarizable embedding hybrid quantum-classical approach and resulting in accurate estimates of redox potentials of biological macromolecules. A special attention is paid to fundamental aspects of the theoretical description such as the effects of environment polarization and of the long-range electrostatic interactions on the computed energetic parameters.

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