The molecular R-matrix with pseudo-states (MRMPS) method is employed to study positron collisions with H2. The calculations employ pseudo-continuum orbital sets containing up to h (l = 5) functions. Use of these high l functions is found to give converged eigenphase sums. Below the positronium formation threshold, the calculated cross sections agree with other high-accuracy theories and generally with the measurements. Calculation of the positron annihilation parameter Zeff with the MRMPS wavefunctions gives values significantly higher than other R-matrix wavefunctions but still do not completely converge with h functions. Extrapolation to higher l-values leads to a predicted value of Zeff for H2 of about 10.4. The MRMPS method is both completely general and ab initio; it can therefore be applied to positron collisions with other molecular targets.
Autorzy
- Rui Zhang,
- K Baluja,
- dr hab. Jan Franz link otwiera się w nowej karcie ,
- Jonathan Tennyson
Informacje dodatkowe
- DOI
- Cyfrowy identyfikator dokumentu elektronicznego link otwiera się w nowej karcie 10.1088/0953-4075/44/3/035203
- Kategoria
- Publikacja w czasopiśmie
- Typ
- artykuł w czasopiśmie wyróżnionym w JCR
- Język
- angielski
- Rok wydania
- 2011