Angular dependence of Gaussian‐Lobe orbitals. II. Set of axial Gaussian‐Lobe orbitals

Abstract

AbstractsThe topological properties of real spherical harmonic representations on the unit sphere have been found to provide a convenient tool to infer the lobe edifices which mimic these orbitals. The prohibitive number of lobes required in such an approach for 1 > 2, can be avoided in using only axial Gaussian-lobe orbitals

Single-centre expansion of Gaussian basis functions and the angular decomposition of their overlap integrals

“…Using equation (3) this formula enables us to calculate the angular momentum composition of an orbital given as an expansion in Gaussian lobe functions in a very efficient way. Similar formulae were used by Le Rouzo and Silvi (1978) for analysing the multipole components of a spatial arrangement of lobe functions. For the computation of the modified spherical Bessel functions there are standard subroutines commonly available in several numerical libraries, for instance in the CPC program library (Thompson and Barnett 1987).…”

Convergency of some properties of electrostatically interacting molecules from accurate CI multipole function calculations

“…Within this framework standard four lobe orbitals are employed as 3drt functions while axial gaussian lobe orbitals (AGLO) [19] describe the 3da, 4[a and 4frr polarization functions. The parameters involved in the lobe representation have been thoroughly optimized [19], allowing an accurate angular dependence as well as an improved connection with cartesian or harmonic GTOs. The unpolarized atomic basis sets used in this calculation are respectively for H, F and C1 the 4s [20], 5s, 3p [20] and 10s, 6p [21] contractions proposed by Dunning.…”

“…Since 8 and r molecular orbitals do not contribute to the SCF ground state wavefunction and very weakly improve the calculated moments at the CI level [13], only a and rr functions have been introduced. Gaussian lobe [17][18][19] orbitals have been used as basis functions. Within this framework standard four lobe orbitals are employed as 3drt functions while axial gaussian lobe orbitals (AGLO) [19] describe the 3da, 4[a and 4frr polarization functions.…”

“…Gaussian lobe [17][18][19] orbitals have been used as basis functions. Within this framework standard four lobe orbitals are employed as 3drt functions while axial gaussian lobe orbitals (AGLO) [19] describe the 3da, 4[a and 4frr polarization functions. The parameters involved in the lobe representation have been thoroughly optimized [19], allowing an accurate angular dependence as well as an improved connection with cartesian or harmonic GTOs.…”