Tunneling currents in long-distance electron transfer reactions. IV. Many-electron formulation. Nonorthogonal atomic basis sets and Mulliken population analysis

1998 ◽  
Vol 108 (20) ◽  
pp. 8510-8520 ◽  
Author(s):  
Alexei A. Stuchebrukhov
Keyword(s):  
Electron Transfer ◽  
Population Analysis ◽  
Transfer Reactions ◽  
Basis Sets ◽  
Mulliken Population Analysis ◽  
Long Distance ◽  
Mulliken Population ◽  
Electron Transfer Reactions ◽  
Tunneling Currents

scholarly journals Ion Ni2+ di Dalam Air; Pembentukan Fungsi Potensial Intermolekul

2010 ◽  
Vol 2 (2) ◽  
pp. 74-82
Author(s):  
Bambang Setiaji ◽  
Tutik Arindah
Keyword(s):  
Standard Deviation ◽  
Potential Function ◽  
Population Analysis ◽  
Pair Potential ◽  
Basis Sets ◽  
Mulliken Population Analysis ◽  
Ab Initio Method ◽  
Mulliken Population ◽  
Net Charge ◽  
Energy Interaction

Pair potential function of Ni2+-H2O system has been constructed by ab initio method at UHF (Unrestricted Hartre-Fock) level. The basis sets used for energy interaction calculation were LANL2 Double-z ECP of Hay and Wadt for Ni2+ and Double-z Polarization of Dunning for H2O. Construction of pair potential function was done by collecting more than 3000 energy points that represent all interactions of Ni2+ ion and water. The pair potential function of Ni2+-H2O resulted of fitting proses by standard deviation of 3,25 kcal/mol is where AiM, BiM, CiM  and DiM are fitting parameter of Ni2+-O or Ni2+-H, riM is distance of i atoms between H2O and Ni2+, q is charge of i atoms of H2O resulted by Mulliken population analysis, and qM is net charge of Ni2+ ion.   Keywords: Ni2+ ion in water, intermoleculer potential function.

ELECTRON TRANSFER REACTIONS COUPLED TO PROTON TRANSLOCATION: CYTOCHROME OXIDASE, PROTON PUMPS, AND BIOLOGICAL ENERGY TRANSDUCTION

2003 ◽  
Vol 02 (01) ◽  
pp. 91-118 ◽  
Author(s):  
ALEXEI A. STUCHEBRUKHOV
Keyword(s):  
Electron Transfer ◽  
Oxygen Reduction ◽  
Cytochrome Oxidase ◽  
Molecular Mechanisms ◽  
Proton Gradient ◽  
Transfer Reactions ◽  
Proton Pumps ◽  
Main Question ◽  
Long Distance ◽  
Electron Transfer Reactions

Cytochrome oxidase (COX) is the terminal component of electron transport chain of the respiratory system in mitochondria, and one of the key enzymes responsible for energy generation in cells. COX functions as a proton pump that utilizes free energy of oxygen reduction for translocation of protons across the mitochondrion membrane. The proton gradient created in the process is later utilized to drive synthesis of ATP. Although the structure of COX has been recently resolved, the molecular mechanism of proton pumping remains unknown. In this paper, general principles and possible molecular mechanisms of energy transformations in this enzyme will be discussed. The main question is how exactly chemical energy of oxygen reduction and water formation is transformed into a proton gradient; or, how exactly electron transfer reactions are utilized to translocate protons across the mitochondrion membrane against the electrochemical gradient. A key to the solution of this problem is in understanding correlated transport of electrons and protons. Here, theoretical models are discussed for coupled electron and proton transfer reactions in which an electron is tunneling over long distance between two redox cofactors, and a coupled proton is moving along a proton conducting channel in a classical, diffusion-like random walk fashion. Such reactions are typical for COX and other enzymes involved in biological energy transformations.

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