Molecular geometry-dependent atomic charge calculation with modified charge equilibration method
نویسندگان
چکیده
We have improved a modified charge equilibration (MQEq) method for calculating the geometry-dependent distribution of atomic charges. In this paper, Ohno-Klopman, Ohno and DasGupta-Huzinaga equations are adopted to express the shielding effect, and the calculated atomic charges with these MQEq methods are in good agreement with those by the HF/6-31G(d,p) calculations for several organic molecules. These MQEq methods would be useful to estimate the charge distribution for large molecules.
منابع مشابه
Atomic Charge Parameters for the Finite Difference Poisson-Boltzmann Method Using Electronegativity Neutralization.
An optimization of Rappe and Goddard's charge equilibration (QEq) method of assigning atomic partial charges is described. This optimization is designed for fast and accurate calculation of solvation free energies using the finite difference Poisson-Boltzmann (FDPB) method. The optimization is performed against experimental small molecule solvation free energies using the FDPB method and adjust...
متن کاملQuantum Chemical Modeling of N-(2-benzoylphenyl)oxalamate: Geometry Optimization, NMR, FMO, MEP and NBO Analysis Based on DFT Calculations
In the present work, the quantum theoretical calculations of the molecular structure of the (N-(2-benzoylphenyl) oxalamate has been investigated and are evaluated using Density Functional Theory (DFT). The geometry of the title compound was optimized by B3LYP method with 6-311+G(d) basis set. The theoretical 1H and 13C NMR chemical shift (GIAO method) values of the title compound are calculated...
متن کاملModeling of the hydration shell of Adenine
The molecular geometry of complex of adenine with 8 water molecules was calculated with Hartree-Fock (HF). The standard 6-31G(d) basis set has been employed. The existence of C-H…O Hydrogen bonds between the water molecules and the hydrophobic part of nucleobase is stablished. We optimized structures and computed interaction energies of all complexes of adenine with water molecules step by step...
متن کاملAb initio and charge study of phospholipids in gas phase and solution
phospholipids are important for the biological lipid and are commonly used in biophysical studies.A quantumcalculation for two phospholipids Dipalmitoylphosphatidylethanolamine and dipalmitoylphosphatidic acidwere performed using the abinitio software. Geometry optimization structures were obtained at RHF level using3-21G, 6-31G*. These basis sets were used To understanding the effects of envir...
متن کاملMerging bond-order potentials with charge equilibration.
A method is presented for extending any bond-order potential (BOP) to include charge transfer between atoms through a modification of the split-charge equilibration (SQE) formalism. Variable limits on the maximum allowed charge transfer between atomic pairs are defined by mapping bond order to an amount of shared charge in each bond. Charge transfer is interpreted as an asymmetry in how the sha...
متن کامل