TY - JOUR

T1 - The generator coordinate method for molecular wavefunctions

T2 - A moment method and a simple intrinsic function

AU - Laskowski, Bernard

AU - Diamond, James

AU - Waleh, Ahmad

AU - Hudson, Bruce

PY - 1978

Y1 - 1978

N2 - An extension of the generator coordinate method to the description of the electronic structure of molecules is presented. An exact formal solution to the Hill-Wheeler equation is obtained for a certain class of intrinsic functions, namely, those whose Hamiltonian and overlap kernels are of degenerate form. Since the exact kernels are used in the Hill-Wheeler equation, the variational principle is retained. The formal solution is represented by the set of moments of the generator coordinate with respect to the weighting function. The features of the method are illustrated by application to the hydrogen molecule. A simple trial intrinsic function and a PPP Hamiltonian are used to describe the π-electron structure of three linear conjugated polyenes (1,3-butadiene; 1,3,5-hexatriene; and 1,3,5,7-octatetraene). A significant part of the apparent ground state correlation energy is recovered for each molecule and π-electron excited state energies are also calculated. These results are compared with PPP CI calculations and the limitations of this simple trial intrinsic function are discussed.

AB - An extension of the generator coordinate method to the description of the electronic structure of molecules is presented. An exact formal solution to the Hill-Wheeler equation is obtained for a certain class of intrinsic functions, namely, those whose Hamiltonian and overlap kernels are of degenerate form. Since the exact kernels are used in the Hill-Wheeler equation, the variational principle is retained. The formal solution is represented by the set of moments of the generator coordinate with respect to the weighting function. The features of the method are illustrated by application to the hydrogen molecule. A simple trial intrinsic function and a PPP Hamiltonian are used to describe the π-electron structure of three linear conjugated polyenes (1,3-butadiene; 1,3,5-hexatriene; and 1,3,5,7-octatetraene). A significant part of the apparent ground state correlation energy is recovered for each molecule and π-electron excited state energies are also calculated. These results are compared with PPP CI calculations and the limitations of this simple trial intrinsic function are discussed.

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U2 - 10.1063/1.436575

DO - 10.1063/1.436575

M3 - Article

AN - SCOPUS:36749105758

SN - 0021-9606

VL - 69

SP - 5222

EP - 5230

JO - The Journal of Chemical Physics

JF - The Journal of Chemical Physics

IS - 12

ER -