✍ Scribed by Masanori Tachikawa; Kazuhide Mori; Kazunari Suzuki; Kaoru Iguchi
No coin nor oath required. For personal study only.
Optimal Gaussian-type orbital GTO basis sets of positron and electron in positron-molecule complexes are proposed by using the full variational treatment of Ž . molecular orbital FVMO method. The analytical expression for the energy gradient with respect to parameters of positronic and electronic GTO such as the orbital exponents, the Ž . orbital centers, and the linear combination of atomic orbital LCAO coefficients, is derived. Wave functions obtained by the FVMO method include the effect of electronic or positronic orbital relaxation explicitly and satisfy the virial and Hellmann᎐Feynman theorems completely. We have demonstrated the optimization of each orbital exponent in Ž . various positron-atomic and anion systems, and estimated the positron affinity PA as the difference between their energies. Our PA obtained with small basis set is in good agreement with the numerical Hartree᎐Fock result. We have calculated the OH y and w y q x OH ; e species as the positron-molecular system by the FVMO method. This result shows that the positronic basis set not only becomes more diffuse but also moves toward the oxygen atom. Moreover, we have applied this method to determine both the nuclear and electronic wave functions of LiH and LiD molecules simultaneously, and obtained the isotopic effect directly.
📜 SIMILAR VOLUMES
We have already proposed a convenient method to estimate the magnitude of the Peierls Ž . instability in finite one-and two-dimensional 1D and 2D polyenes from the viewpoint w Ž .x of orbital symmetry J. Chem. Phys., 103, 9726 1995 . This treatment is applied to a model system for charge-transfer co