Nanopartmles have been used as an approach to improve the pharmacodynamic and phannacokinetie propertiesof various drues. Amino acids have been considered to be useful to make such nano particles because ofthocompatithe and biodegradable characteristic. The quantum mechanical method that was chosen to analyze inethio hexa peptide nano ring]. The structure of some peptide nanorrigs as well as th...

These notes describe the multiconfigurational self-consistent-field (MCSCF) method, which is a general approach for describing chemical systems in which a single electron configuration is no longer an adequate description of the electronic structure. This commonly happens in reactions that break or form chemical bonds, diradicals, and metals of the first transition row. A single-determinant, re...

We extend the relativistic Hartree-Fock (RHF) theory to study structure of single-$\Lambda$ hypernuclei. The density dependence is taken in both meson-nucleon and meson-hyperon coupling strengths, induced $\Lambda$-nucleon ($\Lambda N$) effective interactions are determined by fitting $\Lambda$ separation energies experimental data for several equilibrium nuclear dynamics described RHF model no...

Restricted Hartree-Fock (RHF) and UHF wavefunctions for beryllium-like ions with nuclear charge 3 ≤ Z ≤ 5 are found using a near-complete Slater basis set. The triplet (RHF → UHF) instability and correlation energy are investigated as a function of Z and we find that the instability vanishes for Z > 4.5. We reproduce this surprising behavior using a minimal-basis model and, by comparing with th...

Background: At the forefront of nuclear science, unstable nuclei are special significance, in which deformation and pairing correlations play an essential role determining structure. Under mean field approach, effects have been uniformly considered within deformed nonrelativistic Hartree-Fock-Bogoliubov model relativistic Hartree-Bogoliubov (D-RHB) model. However, due to limitation Hartree impo...

Krüger some years ago proposed a cluster LiBeBCNOF, now called periodane. His ground-state isomer proposal has recently been refined by Bera et al. using DFT. Here, we take the approach of molecules in such a cluster as starting point. We first study therefore the triangular molecule LiOB by coupled cluster theory (CCSD) and thereby specify accurately its equilibrium geometry in free space. The...

Analytic second derivatives of the energy with respect to nuclear coordinates have been developed for spin restricted density functional theory (DFT) based on the fragment molecular orbital method (FMO). The derivations were carried out for the three-body expansion (FMO3), and the two-body expressions can be obtained by neglecting the three-body corrections. Also, the restricted Hartree-Fock (R...

Msller-Plesset perturbation calculations (MPn) up to fiftieth order, within both the restricted (RHF) and unrestricted Hartree-Fock (UHF) frameworks, have been used to examine the He:+ ground-state potential curve. The bond lengths of the equilibrium and transition structures have been optimized at all orders of perturbation theory. It is found that RMPn describes the homolytic dissociation bet...

A family of real Hamiltonian forms (RHF) for the special class of affine 1 + 1dimensional Toda field theories is constructed. Thus the method, proposed in [1] for systems with finite number of degrees of freedom is generalized to infinite-dimensional Hamiltonian systems. We show that each of these RHF is related to a special Z2symmetry of the system of roots for the relevant Kac-Moody algebra. ...

Calculations on NaCl microsolvated with up to 10 water molecules were performed by treating the NaCl with restricted Hartree−Fock (RHF) 6-31G(d) ab initio wave functions and the waters with the effective fragment potential (EFP) model. Increasing numbers of local minima are found with the addition of successive water molecules. As the number of waters is increased, the Boltzmann-averaged NaCl b...