Electron density analysis by quantum chemical calculation.

Chemical Simulation and Quantum Chemical Calculation of Lignin Model Compounds

The conformational preferences of the lignin guaiacyl structural unit were studied by several quantitative chemistry calculation methods using vanillin as a model compound. The potential energy surfaces of the vanillin molecule were scanned by the methods of HF and DFT to find the most stable conformation, as well as three local minimum conformations and six transient conformations. Bonds stren...

Numerical Study of Non - Equilibrium Air Dissociation For Calculation of Electron Density in Hypersonic Flow

Calculation of chemical reaction energies using the AM05 density functional

We present results that compare the accuracy of the AM05 density functional (Armiento and Mattsson, Phys Rev B 2005, 72, 085108; Mattsson et al., J Chem Phys 2008, 128, 084714) to a set of chemical reaction energies. The reactions were generated from the singlet species in the well-known G2 test suite (Curtiss et al., J Chem Phys 1991; Curtiss et al., J Chem Phys 1997; 106, 1063). Our results s...

Density functional calculation of nuclear magnetic resonance chemical shifts

A current-density functional theory for the calculation of nuclear magnetic resonance chemical shifts is presented. If the Kohn–Sham orbitals are expanded in a finite basis set, one of the main problems is the strong dependency of the results with respect to a shift of the gauge origin of the vector potential which describes the external magnetic field. Two computational schemes implementing bo...

Electron energy level calculation for a three dimensional quantum dot

Abstract: In this paper we consider the rational eigenvalue problem governing the relevant energy levels and wave functions of a three dimensional quantum dot. We present iterative projection methods of Arnoldi and of Jacobi–Davidson type for computing a few eigenpairs of this system. Solving the projected nonlinear eigenvalue problems we take advantage of a minmax characterization of the eigen...