AbstractsH$-type elliptical orbitals are defined in Section 1. These orbitals, which in elliptical coordinates involve a factor (1 + Q", are employed in variational calculations on the ground states of H$ and H, (Sections 2 and 3). Various choices of u are explored for Hk, while two choices are used for H, : the "boundary condition" (Equation 6) and the "cusp Three four-function basis sets are used, and the best energy is -1.2306 a.u., which is in reasonable agreement with the Hartree-Fock limit, -1.2999 a.u. Our best basis set is a four-term two-center expansion of the wave function with only one nonlinear variational parameter. Section 5 concludes the paper with a summary of the methods used to evaluate the integrals which arise in SCF calculations in the H$-type elliptical orbital basis.
A study is made of the electron distribution generated by self-consistent field wavefunctions for the hydrogen molecule–helium atom system. The electron density is studied by means of electron density contour plots and plots of the difference between the electron density for interacting hydrogen molecule and helium atom systems and the noninteracting hydrogen molecule and helium atom. A population analysis technique is applied to these wavefunctions. Though the population analysis is a rather unrealistic method of distributing the electrons among and between the nuclei, it appears to give a qualitatively correct description of the electron distribution. The wavefunction studied gives a potential surface on which the H2 molecule tends to contract when the He atom approaches. This is true even when He approaches the H2 at an angle of 90° to the internuclear axis. The population analysis reflects this effect by showing an increase in the H2 bond population as He approaches.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.