Positrons annihilating in hexane and decane

Abstract

In a previous paper (1), we calculated the momentum distributions of electrons in the C-C and C-H bonds using SCF valence bond electron wave functions. When these calculations were compared with experimental distributions of hexane and decane obtained from positron annihilation angular-correlation experiments, good fits were obtained for all but the high-momentum region. This discrepancy may be a t t r ibuted to the use of a constant positron wave function in the calculation. In this paper, we present the calculated momentum distr ibutions of photon pairs due to positrons annihilating with electrons in hexano and decane employing a positron wave function, which takes into account the interaction between a positron and the effective atomic nuclei, introduced by us (3) in calculations for positrons annihilat ing in solid and liquid methane. The calculation of the momentum distr ibution of the annihilating positron-electron pairs in the C-H bond, N(C-H), has been carried out in detail by CHUA~G et al. (2). The calculation of the momentum distr ibution of the annihilating pairs in the C-C bond, N(C-C), is similar to tha t of the iV(C-H), and the result is presented as follows: