In the present paper the mechanism behind the neutron generation experiment in titanium lattice alloyed with deuterium atoms is investigated via both a static Density Functional Theory and a Molecular Dynamics approach. In particular, the hypothesized formation of a three-centre-two-electrons (3c-2e) bond, which is typical of electron-deficient species alloyed with H and its heavy isotopes (D, T), is investigated. In the context of the static analysis, a two-fold approach is taken into account, i.e., a cluster one to describe the bonding environment and the nature of the orbitals involved in such a bond, and a periodic one through which the occurrence of this peculiar feature is investigated as a function of deuterium atom concentrations in the Ti lattice. The octahedral subcell is found to be the most suitable site for the formation of this bond. A saturation value of two deuterium atoms for the 3c-2e bond per octahedral/tetrahedral subcell is also reported. Molecular Dynamics analysis performed at ordinary T by means of a Nose thermostat reveals the possibility for two deuterium atoms to occupy at the same time the T-d and the O-h site of vicinal subcells.
Neutron generation via the mechanism adsorption of pressurized deuterium on an electron deficient titanium matrix. An MD-DFT combined analysis on the mechanism of the Ti-D bond formation
GIORGI, Giacomo;BELANZONI, Paola;
2012
Abstract
In the present paper the mechanism behind the neutron generation experiment in titanium lattice alloyed with deuterium atoms is investigated via both a static Density Functional Theory and a Molecular Dynamics approach. In particular, the hypothesized formation of a three-centre-two-electrons (3c-2e) bond, which is typical of electron-deficient species alloyed with H and its heavy isotopes (D, T), is investigated. In the context of the static analysis, a two-fold approach is taken into account, i.e., a cluster one to describe the bonding environment and the nature of the orbitals involved in such a bond, and a periodic one through which the occurrence of this peculiar feature is investigated as a function of deuterium atom concentrations in the Ti lattice. The octahedral subcell is found to be the most suitable site for the formation of this bond. A saturation value of two deuterium atoms for the 3c-2e bond per octahedral/tetrahedral subcell is also reported. Molecular Dynamics analysis performed at ordinary T by means of a Nose thermostat reveals the possibility for two deuterium atoms to occupy at the same time the T-d and the O-h site of vicinal subcells.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
