Convergent S. C. F. Wave Function and Properties of the Ammonia Molecule

1965 ◽  
Vol 20 (12) ◽  
pp. 1557-1565 ◽  
Author(s):  
P. Rajagopal
Keyword(s):  
Wave Function ◽  
Ammonia Molecule ◽  
Quadrupole Moments ◽  
Dissociation Energies ◽  
Self Consistent Field ◽  
Molecular Integrals ◽  
Function Calculation ◽  
F Wave ◽  
Numerical Integration Methods ◽  
Field Wave

A self consistent field wave function calculation for the ammonia molecule by the technique of accumulative accuracy is described. The molecular integrals required are calculated by numerical integration methods. Total and dissociation energies, dipole and quadrupole moments and ionization potentials calculated using the wave function are reported. The proton affinity of NH3 is also estimated.

Quadratic response functions for a multiconfigurational self‐consistent field wave function

1992 ◽  
Vol 97 (2) ◽  
pp. 1174-1190 ◽  
Author(s):  
Hinne Hettema ◽  
Hans Jo/rgen Aa. Jensen ◽  
Poul Jo/rgensen ◽  
Jeppe Olsen
Keyword(s):  
Wave Function ◽  
Response Functions ◽  
Consistent Field ◽  
Self Consistent ◽  
Self Consistent Field ◽  
Quadratic Response ◽  
Field Wave

scholarly journals Multiconfiguration Pair-Density Functional Theory for Transition Metal Silicide Bond Dissociation Energies, Bond Lengths, and State Orderings

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2881
Author(s):  
Meagan S. Oakley ◽  
Laura Gagliardi ◽  
Donald G. Truhlar
Keyword(s):  
Wave Function ◽  
Transition Metal ◽  
Density Functional ◽  
Bond Dissociation Energies ◽  
Complete Active Space ◽  
Active Space ◽  
Bond Dissociation ◽  
Dissociation Energies ◽  
Pair Density ◽  
Self Consistent Field

Transition metal silicides are promising materials for improved electronic devices, and this motivates achieving a better understanding of transition metal bonds to silicon. Here we model the ground and excited state bond dissociations of VSi, NbSi, and TaSi using a complete active space (CAS) wave function and a separated-pair (SP) wave function combined with two post-self-consistent field techniques: complete active space with perturbation theory at second order and multiconfiguration pair-density functional theory. The SP approximation is a multiconfiguration self-consistent field method with a selection of configurations based on generalized valence bond theory without the perfect pairing approximation. For both CAS and SP, the active-space composition corresponds to the nominal correlated-participating-orbital scheme. The ground state and low-lying excited states are explored to predict the state ordering for each molecule, and potential energy curves are calculated for the ground state to compare to experiment. The experimental bond dissociation energies of the three diatomic molecules are predicted with eight on-top pair-density functionals with a typical error of 0.2 eV for a CAS wave function and a typical error of 0.3 eV for the SP approximation. We also provide a survey of the accuracy achieved by the SP and extended separated-pair approximations for a broader set of 25 transition metal–ligand bond dissociation energies.

Hexaborane(10). Self-consistent field wave function, localized orbitals, and relations to chemical properties

1971 ◽  
Vol 10 (1) ◽  
pp. 171-181 ◽  
Author(s):  
William N. Lipscomb ◽  
Irving R. Epstein ◽  
John A. Tossell ◽  
Eugene Switkes ◽  
Richard Morton Stevens
Keyword(s):  
Wave Function ◽  
Chemical Properties ◽  
Localized Orbitals ◽  
Consistent Field ◽  
Self Consistent ◽  
Self Consistent Field ◽  
Field Wave

Relativistic effects in atomic and molecular properties

2010 ◽  
Vol 60 (3) ◽  
Author(s):  
Miroslav Iliaš ◽  
Vladimír Kellö ◽  
Miroslav Urban
Keyword(s):  
Heavy Metal ◽  
Relativistic Quantum ◽  
Relativistic Effects ◽  
Molecular Properties ◽  
Quadrupole Moments ◽  
Basic Principles ◽  
Dissociation Energies ◽  
Heavy Metal Element ◽  
The Many ◽  
Nuclear Quadrupole Moments

Relativistic effects in atomic and molecular propertiesWe present an overview of basic principles and methods of the relativistic quantum chemistry. Practical aspects of different methods will be discussed stressing their capability of providing accurate predictions of molecular properties, particularly in species containing a heavy metal element. We will present a series of examples showing the importance of relativistic effects in a variety of molecular properties including electron affinities, ionization potentials, reaction and dissociation energies, electric, spectroscopic and other properties. It is possible to recognize a link between these properties and behaviour of materials in some cases. Particular attention is paid to relativistic calculations of the nuclear quadrupole moments for which accurate theoretical electric field gradient is combined with data from the microwave spectra. Important aspect of the present paper is understanding of trends in electronically related atoms throughout the Mendeleev Periodic Table rather than focusing on highly accurate numbers. We will show that relativistic effects represent an unavoidable instrument for explaining some unexpected properties of heavy metal containing compounds. We will also discuss an interplay between the many-electron correlation and relativistic effects.

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