Relativistic ab initio calculations have been performed to assess the suitability of RaF for experimental search of P− and T,P−violating interactions. The parameters of P− and T,P−odd terms of the spin-rotational Hamiltonian have been calculated for the 2 Σ electronic ground state of 223 RaF molecule. They include the Wa parameter, which is critical in experimental search for nuclear anapole moment and the parameters W d and WSP required to obtain restrictions on the electric dipole moment of the electron and T,P−odd scalar−pseudoscalar interactions, respectively. The parameter X corresponding to the "volume effect" in the T,P−odd interaction of the 223 Ra nuclear Schiff moment with electronic shells of RaF has also been computed. Spectroscopic and hyperfine structure constants for 223 RaF and 223 Ra + have been computed as well, demonstrating the accuracy of the methods employed.

The relativistic coupled-clusters method combined with the generalized relativistic effective core potential approach and nonvariational one-center restoration technique is applied to evaluation of parameters of the spin-rotational effective Hamiltonian in lead monofluoride to study the effects of violation of time-reversal invariance (T ) and space parity (P ) in PbF. The obtained hyperfine structure constants, A || = 9942 MHz and A ⊥ = −7174 MHz, are stable with respect to the improvement of the correlation treatment, and they are in very good agreement with the experimental data, A || = 10 147 MHz and A ⊥ = −7264 MHz [R. Phys. Rev. A 84, 022508 (2011); A. N. Petrov, L. V. Skripnikov, A. V. Titov, and R. J. Mawhorter, ibid. 88, 010501(R) ( 2013)]. This is essential to the important task of verifying the value of effective electric field E eff = 40 GV/cm, the parameter of P -odd interaction W P = −1213 Hz, and the parameter of T ,P -odd pseudoscalar-scalar electron-nucleus interaction W T ,P = 91 kHz, which are of primary interest in the Brief Report.

The 10-electron generalized relativistic effective core potential and the corresponding correlation spin-orbital basis sets are generated for the Ra atom and the relativistic coupled cluster calculations for the RaO molecule are performed. The main goal of the study is to evaluate the T,P-odd parameter X characterized by the molecular electronic structure and corresponding to a "volume effect" in the interaction of the 225 Ra nucleus Schiff moment with electronic shells of RaO. Our final result for X( 225 RaO) is −7532 which is surprisingly close to that in 205 TlF but has a different sign. The obtained results are discussed and the quality of the calculations is analyzed. The value is of interest for a proposed experiment on RaO [PRA 77, 024501 (2008)] due to a very large expected Schiff moment of the 225 Ra nucleus.