1. Progress report: Calculations on BeH+
Åsa Larson, Stockholm University
Johanna Roos, Stockholm University
Ann Orel, UC Davis
Mats Larsson, Stockholm University

3. Motivation Beryllium used for the first wall and limiter
BeH+ formed in the plasma
How fast does it recombine with electrons?
Problem: toxicity of Be; experiments not the preferred choice

4. What has been done
Theoretical work on BexHy was reported by Stefan Matejcik at the CRP-meeting in June 2007
High resolution spectroscopy work on BeH published in 2006 (Le Roy et al. J.Mol.Spec.)
High resolution work on BeH+ published by Coxon & Colin, J. Mol. Spec. 1997
Theoretical calculations by several groups

6. Re (Å)
e (cm-1)
De (eV)
1984
1.3428
2.162
2008
1.345
2.133
Exp. 2006
2.181

7. JCP 2008

8. Dissociative recombination
Be + H
BeH+ + e

9. Results for diatomic hydrides
HeH+
LiH+
BeH+
BH+
CH+
NH+
OH+
FH+
The.
yes no
Exp.

12. MRCI calculations on the excited states of the ion:

13. MRCI calculations on the excited states of BeH (2A1 symmetry)

14. MRCI calculations on the excited states of BeH (2A2 symmetry)

15. MRCI calculations on the excited states of BeH (2B1 symmetry)

16. Electron scattering calculations
Using the Complex Kohn variational method, the resonant states of BeH are calculated.
Trial wave function:
Insert into a variational functional for the T-matrix ci, dμ, T
Eigenphase sum of the T-matrix: Eres(R), Γres(R)
Target wave function MRCI
Correlation and polarization

17. Eigenphase sum: 2A1 symmetry (2Σ+, 2∆) R = 2.5 a0

18. Combine resonant potentials obtained with the electron scattering calculation with the electronically bound states obtained with structure calculation.
Quasidiabatization
2Σ+ symmetry:

19. 2Π symmetry

20. 2∆ symmetry

21. Molecular Dynamics with a time-independent nonlocal model
The driven time-independent SE
The resonant state potential
PRA 71, (2005)
The driving term or ”entry amplitude”
Partial cross section
Total cross section

22. Cross sections Partial cross section for Δ states
Total cross section

23. Concluding remarks
The calculations will be finalized with nonadiabatic couplings included
CRYRING will be used for a few experiments during 2009, and then in 2010 moved to Darmstadt (FAIR)
A new double electrostatic storge ring, Desiree, will be commissioned in Stockholm during 2009