Distributed Gaussian basis sets: Variationally optimized <i>s‐</i>type sets for the open‐shell systems HeH and BeH

Glushkov, V. N.; Wilson, Stephen

doi:10.1002/qua.20143

Cited by 29 publications

(20 citation statements)

References 40 publications

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“…This makes it possible to minimize the error associated with truncation of one-particle basis sets and, thus, to observe more clearly the errors of the method itself. More information about of such basis sets can be found in [14,15]. We compare our results with those of the precisional ab initio calculations obtained with extended basis sets and experimental data [16,17].…”

Section: Applications To Electronic Excitation Energiesmentioning

confidence: 50%

Excitation Energies from a Partially Spin-Restricted Wave Function

Glushkov¹

2007

Computing Letters

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A singe Slater determinant consisting of restricted and unrestricted, in spins, parts is proposed to construct a reference configuration for singlet excited states having the same symmetry as the ground one. A partially restricted Hartree-Fock approach is developed to derive amended equations determining the spatial molecular orbitals for singlet excited states. They present the natural base to describe the electron correlation in excited states using the wellestablished spin-annihilated perturbation theories. The efficiency of the proposed method is demonstrated by calculations of electronic excitation energies for the Be atom and LiH molecule.

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Section: Applications To Electronic Excitation Energiesmentioning

confidence: 50%

Excitation Energies from a Partially Spin-Restricted Wave Function

Glushkov¹

2007

Computing Letters

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“…Although the parameters defining the basis sets, ζ k p and R k p , can be determined by invoking the variation principle [92][93][94][95], it has been established that the even-tempered prescription in which the exponents are taken to form a geometric sequence:…”

Section: Distributed Gaussian Basis Sets For Ground and Excited Statesmentioning

confidence: 99%

The Coulson–Fischer wave functions for the ground and excited states of H₂and HeH⁺: parametrisation using distributed Gaussian basis sets

Glushkov

Wilson

2014

Molecular Physics

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Coulson-Fischer wave functions are used to determine complete potential energy curves for the X 1 + g ground state of the H 2 molecule and for the first excited state EF 1 + g having the same symmetry. The Coulson-Fischer orbitals are parametrised by expansion in distributed Gaussian basis sets of s-type functions. The exponents of the Gaussian functions are generated by using an even-tempered prescription. An anharmonic model is used to locate the basis functions along the internuclear axis. Sequences of basis sets are used to reduce the basis set truncation error to the sub-μhartree level. Equations are derived to determine the generalised Coulson-Fischer orbitals for the excited state which ensure that orthogonality conditions with respect to the ground state are satisfied. Potential energy curves are also calculated using smaller basis sets for which both exponents and basis function positions are determined by invoking the variation principle. The results of calculations for the isoelectronic heteronuclear HeH + ion are also reported. The potential energy curves obtained in the present study are compared with literature values for both H 2 and HeH + .

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“…In our previous papers [44][45][46], we have presented variationally optimized distributed Gaussian basis sets containing only functions s-type for some simple molecules. We demonstrated that a sub-µ Hartree level of accuracy can be supported by basis sets of modest size.…”

Section: Comparison Of the Anharmonic Distribution With Variationallymentioning

confidence: 99%

“…The emphasis of our recent investigations for small diatomic molecules [44][45][46] was to design fully optimized s-type distributed basis sets capable of supporting energies of sub-µHartree accuracy at the Hartree-Fock level. Certainly, such variational calculations involve a time-consuming nonlinear optimization process for both exponents and positions and cannot be used for routine calculations on arbitrary systems.…”

Section: Introductionmentioning

confidence: 99%

Distributed basis sets of s‐type Gaussian functions for simple diatomics: Anharmonic‐model distribution

Glushkov

Wilson

2007

Int J of Quantum Chemistry

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An and H 2 diatomic systems. The total ground state energies for the one-electron systems and the ground state Hartree-Fock energy for the H 2 molecule supported by distributed basis sets constructed by means of the anharmonic model are compared with the corresponding energies obtained by invoking the variation principle to determine optimal exponents and positions. The use of a series of anharmonic distributions of s-type Gaussian functions centred on regularly spaced points is also investigated. Calculated energy expectation values supported by our largest distributed basis sets differ from the corresponding exact values by 0.70 µHartree for the H + 2 ion and by 0.89 µHartree for the HeH 2+ ion. For the ground state Hartree-Fock energy of the H 2 molecule, our distributed basis set yields a value which differs from the finite difference Hartree-Fock value by 0.67 µHartree.

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Distributed Gaussian basis sets: Variationally optimized s‐type sets for the open‐shell systems HeH and BeH

Abstract: Distributed basis sets of s-type

Cited by 29 publications

References 40 publications

Excitation Energies from a Partially Spin-Restricted Wave Function

Excitation Energies from a Partially Spin-Restricted Wave Function

The Coulson–Fischer wave functions for the ground and excited states of H₂and HeH⁺: parametrisation using distributed Gaussian basis sets

Distributed basis sets of s‐type Gaussian functions for simple diatomics: Anharmonic‐model distribution

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Distributed Gaussian basis sets: Variationally optimized s‐type sets for the open‐shell systems HeH and BeH

Abstract: Distributed basis sets of s-type

Cited by 29 publications

References 40 publications

Excitation Energies from a Partially Spin-Restricted Wave Function

Excitation Energies from a Partially Spin-Restricted Wave Function

The Coulson–Fischer wave functions for the ground and excited states of H2and HeH+: parametrisation using distributed Gaussian basis sets

Distributed basis sets of s‐type Gaussian functions for simple diatomics: Anharmonic‐model distribution

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The Coulson–Fischer wave functions for the ground and excited states of H₂and HeH⁺: parametrisation using distributed Gaussian basis sets