graphyne and graphdiyne families of flat carbon (sp2/sp) networks with high degrees of π-conjunction are attracting much attention due to their promising electronic, optical, and mechanical properties. in the present investigation we have studied the structural, mechanical, electrical and optical properties of halogenated graphdiyne and graphyne. the optical spectra of pure and halogenated stru...

In order to solve the A-body Schrödinger equation both accurately and efficiently for open-shell nuclei, a novel many-body method coined as Bogoliubov perturbation theory (BMBPT) was recently formalized applied at low orders. Based on breaking of U(1) symmetry associated with particle-number conservation, this must operate under constraint that average number particles is self-consistently adju...

The neon isotopic chain displays a rich phenomenology, ranging from clustering in the ground-state of self-conjugate doubly open-shell stable $^{20}$Ne isotope to physics island inversion around neutron-rich $^{30}$Ne isotope. This second (i.e. Paper II) present series proposes an extensive ab initio study isotopes based on two complementary many-body methods, i.e. quasi-exact in-medium no-core...

We show that the existence of algebraic forms of exactly-solvable A−B− C−D and G2, F4 Olshanetsky-Perelomov Hamiltonians allow to develop the algebraic perturbation theory, where corrections are computed by pure algebraic means. A classification of perturbations leading to such a perturbation theory based on representation theory of Lie algebras is given. In particular, this scheme admits an ex...

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The development of standard MBPT for single-reference and multi-reference cases is reviewed, and its extension to the relativistic case in the form of the Dirac-Coulomb-Breit (DCB) approximation is described. The latter scheme is non-covariant, and the recent development of a fully covariant MBPT scheme is discussed. This is based upon a new scheme for quantumelectrodynamical (QED) calculations...