Polar diatomic molecules that have, or are expected to have a 2 Σ 1/2 -ground state are studied systematically with respect to simultaneous violation of parity P and time-reversal T with numerical methods and analytical models. Enhancements of P, T -violating effects due to an electric dipole moment of the electron (eEDM) and P, T -odd scalar-pseudoscalar nucleon-electron current interactions are analyzed by comparing trends within columns and rows of the periodic table of the elements. For this purpose electronic structure parameters are calculated numerically within a quasi-relativistic zeroth order regular approximation (ZORA) approach in the framework of complex generalized Hartree-Fock (cGHF) or Kohn-Sham (cGKS). Scaling relations known from analytic relativistic atomic structure theory are compared to these numerical results. Based on this analysis, problems of commonly used relativistic enhancement factors are discussed. Furthermore the ratio between both P, T -odd electronic structure parameters mentioned above is analyzed for various groups of the periodic table. From this analysis an analytic measure for the disentanglement of the two P, T -odd electronic structure parameters with multiple experiments in dependence of electronic structure enhancement factors is derived. arXiv:1805.05494v2 [physics.chem-ph]

We present triethylboron (TEB) as a single-source precursor for chemical vapor deposition (CVD) of B x C thin films and study its gas phase chemistry under CVD conditions by quantum chemical calculations.A comprehensive thermochemical catalogue for the species of the gas phase chemistry of TEB is examined and found to be dominated by b-hydride eliminations of C 2 H 4 to yield BH 3 . A complementary bimolecular reaction path based on H 2 assisted C 2 H 6 elimination to BH 3 is also significant at lower temperatures in the presence of hydrogen. Furthermore, we find a temperature window of 600-1000 1Cfor the deposition of X-ray amorphous B x C films with 2.5 r x r 4.5 from TEB. Films grown at temperatures below 600 1C contain high amounts of H, while temperatures above 1000 1C result in C-rich films. The film density and hardness are determined to be in the range of 2.40-2.65 g cm À3 and 29-39 GPa, respectively, within the determined temperature window. † Electronic supplementary information (ESI) available: Tables with more details of the atomic content and measured densities and hardness of the films, and more details of the computations together with Cartesian coordinates of structures. See

A quasi-relativistic two-component approach for an efficient calculation of P, T -odd interactions caused by a permanent electric dipole moment of the electron (eEDM) is presented. The approach uses a (two-component) complex generalized Hartree-Fock (cGHF) and a complex generalized Kohn-Sham (cGKS) scheme within the zeroth order regular approximation (ZORA). In applications to select heavy-elemental polar diatomic molecular radicals, which are promising candidates for an eEDM experiment, the method is compared to relativistic four-component electron-correlation calculations and confirms values for the effective electrical field acting on the unpaired electron for RaF, BaF, YbF and HgF. The calculations show that purely relativistic effects, involving only the lower component of the Dirac bi-spinor, are well described by treating only the upper component explicitly.

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