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Coot can also display electron density, which is the result of structure determination experiments such as X-ray crystallography and EM reconstruction. The density is contoured using a 3D-mesh. The contour level controlled using the mouse wheel for easy manipulation - this provides a simple way for the user to get an idea of the 3D electron ...
Quantum ESPRESSO (Quantum Open-Source Package for Research in Electronic Structure, Simulation, and Optimization; QE) [2] [3] is a suite for first-principles electronic-structure calculations and materials modeling, distributed for free and as free software under the GNU General Public License.
The full name is Program for Atomic and Molecular Direct Iterative Relativistic All-electron Calculations, in short PAM DIRAC. It is capable of calculating various molecular properties using the Hartree–Fock , MP2 , density functional theory , configuration interaction and coupled cluster electronic structure theories.
DMol 3 permits geometry optimisation and saddle point search with and without geometry constraints, as well as calculation of a variety of derived properties of the electronic configuration. DMol 3 development started in the early eighties with B. Delley then associated with A.J. Freeman and D.E. Ellis at Northwestern University . [ 4 ]
The emphasis in the program is on highly accurate computations, with extensive treatment of the electron correlation problem through the multireference configuration interaction, coupled cluster and associated methods. Integral-direct local electron correlation methods reduce the increase of the computational cost with molecular size.
In atomic physics and quantum chemistry, the electron configuration is the distribution of electrons of an atom or molecule (or other physical structure) in atomic or molecular orbitals. [1] For example, the electron configuration of the neon atom is 1s 2 2s 2 2p 6 , meaning that the 1s, 2s, and 2p subshells are occupied by two, two, and six ...
Spartan is a molecular modelling and computational chemistry application from Wavefunction. [2] It contains code for molecular mechanics, semi-empirical methods, ab initio models, [3] density functional models, [4] post-Hartree–Fock models, [5] and thermochemical recipes including G3(MP2) [6] and T1. [7]
The MO diagram for diboron (B-B, electron configuration 1σ g 2 1σ u 2 2σ g 2 2σ u 2 1π u 2) requires the introduction of an atomic orbital overlap model for p orbitals. The three dumbbell -shaped p-orbitals have equal energy and are oriented mutually perpendicularly (or orthogonally ).