Theoretical study of ThF+ in the search for T, P-violation effects: Effective state of a Th atom in ThF+ and ThO compounds

We report the results of a theoretical investigation of the electronic structure of the ThF+ cation, which is one of the most interesting systems to search for the electron electric dipole moment (eEDM) [H. Loh, K. C. Cossel, M. C. Grau, K.-K. Ni, E. R. Meyer, J. L. Bohn, J. Ye, and E. A. Cornell, Science 342, 1220 (2013)] and other effects of violation of time reversal (T) and spatial parity (P) symmetries in fundamental interactions. For the working (3)Delta(1) state we find a quite high value of the effective electric field acting on unpaired electrons (37.3 GV/cm). The field will be required to interpret the experiment planned on ThF+ in terms of the eEDM. Within the concept of atoms in compounds [A. V. Titov, Y. V. Lomachuk, and L. V. Skripnikov, Phys. Rev. A 90, 052522 (2014)], we compare the ThF+ electronic structure with that of ThO. Also, we calculate other parameters of T, P-odd interactions: W-T,W- P, which is needed for interpretation of the experiment in terms of the dimensionless constant k(T, P) characterizing the strength of the T, P-odd pseudoscalar-scalar electron-nucleus neutral current interaction (50 kHz); and W-M, which is required to search for the Th-229 nuclear magnetic quadrupole moment in (ThF+)-Th-229 (0.88 10(33) Hz/e cm(2)). A number of properties which can be measured are also calculated: the hyperfine structure constant, molecule-frame dipole moment, and g factor.