Coulomb holes and correlation coefficients in position space for HeH+

Electron correlation in position space is examined in HeH + , the simplest of heteronuclear systems, as a function of the internuclear separation R. Coulomb holes and various partial Coulomb holes are evaluated and compared for He, HeH + and Li + . Several correlation coefficients tau are also determined. The results are discussed in the light of a recent correlation analysis of HeH + in momentum space. At the theoretical bond length R Th , the Coulomb hole for HeH + in position space is found to be very similar to that obtained for the ground state of He. As in momentum space, each tau which assesses angular correlation shows an increase in magnitude on molecular formation. Of particular interest in position space is the dramatic increase in the importance of 'left-right' correlation along the bond axis when R approaches R Th .