scholarly journals Study on Raffenetti's P File Format in Conventional Ab Initio Self-Consistent-Field Molecular Orbital Calculations in Parallel Computational Environment

2008 ◽  
Vol 7 (5) ◽  
pp. 179-184
Author(s):  
Hiroyuki TERAMAE ◽  
Kazushige OHTAWARA
Keyword(s):  
Ab Initio ◽  
Molecular Orbital ◽  
Molecular Orbital Calculations ◽  
File Format ◽  
Computational Environment ◽  
Consistent Field ◽  
Self Consistent ◽  
Self Consistent Field

Ab initio self-consistent-field molecular-orbital calculations on AlO4 centres in alpha-quartz. II.

1985 ◽  
Vol 63 (10) ◽  
pp. 1282-1293 ◽  
Author(s):  
Michael J. Mombourquette ◽  
John A. Weil
Keyword(s):  
Ab Initio ◽  
Molecular Orbital ◽  
Structural Parameters ◽  
Molecular Orbital Calculations ◽  
Paramagnetic Resonance ◽  
Consistent Field ◽  
Large Channel ◽  
Self Consistent ◽  
Self Consistent Field ◽  
Small Models

In this paper, the second of a series devoted to developing quantitative understanding of defect species in silicates, we report ab initio self-consistent-field molecular-orbital calculations done on 10-atom and 22-atom clusters designed to simulate cation-compensated aluminum impurity centres [AlO4/M+]qt in alpha-quartz; here qt = 0 or + 1, and M = H, Li, or Na. The geometric configurations of the small models of these centres were optimized. The calculated values for total energies, various static structural parameters, electron-spin densities, net atomic charges, and orbital energies are compared with experimental data, especially those derived from electron-paramagnetic-resonance studies of hole centres and give good agreement. For example, the models predict that the holes will occur at opposite types of oxygen ions adjacent to Al3+, respectively, for uncompensated centres [AlO4]0 and for the centres [AlO4/M+]+, as is, in fact, observed. Some calculations for interstitial cations M+ and atomic hydrogen on clusters simulating large-channel c-axis oxygen sites of alpha-quartz are reported. Various reaction energies involving the aluminum centres and the interstitial species are listed.

Ab initio molecular orbital calculations of the ground and excited states of the permanganate and chromate ions

1970 ◽  
Vol 320 (1541) ◽  
pp. 161-173 ◽  
Keyword(s):  
Molecular Orbital ◽  
Excited States ◽  
Slater Type Orbitals ◽  
Molecular Orbital Calculations ◽  
Field Equations ◽  
Chromate Ions ◽  
Consistent Field ◽  
Self Consistent ◽  
Self Consistent Field ◽  
State Wavefunctions

The bonding in the permanganate and chromate ions is described by means of self-consistent field molecular orbital calculations employing a basis of Slater type orbitals expanded in Gaussian type functions. A new procedure for the solution of the self-consistent field equations is described and applied to the ions studied here. Excited state wavefunctions are calculated using configuration interaction considering all singly excited configurations involving all virtual and valence orbitals. The calculated transition energies and transition moments are compared with those from the experimental electronic spectra.

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