Two-step method and high-precision calculation of PNC effects in heavy-atom molecules
N.S.Mosyagin, A.V.Titov, A.N.Petrov, T.A.Isaev
Petersburg Nuclear Physics Institute
The search for the P,T-parity nonconservation (PNC) effects is of
fundamental importance in physics, and such experiments are performed on
TlF and YbF, and are prepared on PbO and HgH. For preparation and interpretation
of these experiments one should calculate electronic densities on the heavy
nuclei and other molecular properties which cannot be measured. The generalized
RECP (GRECP) method  allows one to treat precisely the correlation and
relativistic effects in the valence region of molecules with minimal efforts.
However, the molecular spinors are smoothed in heavy-atom cores and for
the calculation of the core properties one should restore correct shapes
 of the four-component spinors in the cores after a two-component molecular
GRECP calculation. In the report, the GRECP and restoration methods are
presented, which are illustrated on two-step calculation of the PNC effects
in YbF, TlF and PbO.
We are grateful to CRDF for the Grant No. RP2-2339-GA-02 and RFBR for the Grant No. 03--03--32335.
 A.V.Titov, N.S.Mosyagin, Int.J.Quant.Chem. 71,359 (1999)
 A.N.Petrov et al., Phys.Rev.Lett., 88, 073001 (2002).