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DMol 3 is a commercial (and academic) software package which uses density functional theory with a numerical radial function [1] basis set to calculate the electronic properties of molecules, clusters, surfaces and crystalline solid materials [2] from first principles.
The density may be portrayed in terms of an isosurface (isodensity surface) with the size and shape of the surface being given by the value (or percentage of enclosure) of the electron density. Spin density – The density, ρ spin ( r ), is defined as the difference in electron density formed by electrons of α spin, ρα( r ), and the ...
It is capable of calculating various molecular properties using the Hartree–Fock, MP2, density functional theory, configuration interaction and coupled cluster electronic structure theories. Dirac is one of the most successful general-purpose quantum chemistry packages that provides accurate description of relativistic effects in molecules ...
ChemDraw is a molecule editor first developed in 1985 by Selena "Sally" Evans, her husband David A. Evans, and Stewart Rubenstein [1] [2] (later by the cheminformatics company CambridgeSoft).
For any substance, the number density can be expressed in terms of its amount concentration c (in mol/m 3) as = where N A is the Avogadro constant. This is still true if the spatial dimension unit, metre, in both n and c is consistently replaced by any other spatial dimension unit, e.g. if n is in cm −3 and c is in mol/cm 3 , or if n is in L ...
Density is an intensive property in that increasing the amount of a substance does not increase its density; rather it increases its mass. Other conceptually comparable quantities or ratios include specific density , relative density (specific gravity) , and specific weight .
Open Babel is a free chemical informatics software designed to facilitate the conversion of Chemical file formats and manage molecular data. [3] It serves as a chemical expert system, widely used in fields such as cheminformatics, molecular modelling, and computational chemistry.
A special type of area density is called column density (also columnar mass density or simply column density), denoted ρ A or σ. It is the mass of substance per unit area integrated along a path; [ 1 ] It is obtained integrating volumetric density ρ {\displaystyle \rho } over a column: [ 2 ] σ = ∫ ρ d s . {\displaystyle \sigma =\int \rho ...