We introduce a new approach to calculate directly the electric current in Born–Oppenheimer molecular dynamics. In this approach the electric current is computed from the adiabatic variations of the Kohn– Sham eigenstates between consecutive time steps. This conceptually straightforward method is fairly efficient and can be easily implemented into existing electronic structure programs. We test ...

We study the quantum foundations of a theory of large amplitude collective motion for a Hamiltonian expressed in terms of canonical variables. In previous work the separation into slow and fast (collective and non-collective) variables was carried out without the explicit intervention of the Born Oppenheimer approach. The addition of the Born Oppenheimer assumption not only provides support for...

We present the implementation of the time-dependent density-functional theory both in linear-response and in time-propagation formalisms using the projector augmented-wave method in real-space grids. The two technically very different methods are compared in the linear-response regime where we found perfect agreement in the calculated photoabsorption spectra. We discuss the strengths and weakne...

Baryons containing two heavy quarks are treated in the Born-Oppenheimer approximation. Schrödinger equation for two center Coulomb plus harmonic oscillator potential is solved by the method of ethalon equation at large intercenter separations. Asymptotical expansions for energy term and wave function are obtained in the analytical form. Using those formulas, the energy spectra of doubly heavy b...

We propose here an efficient method to define a representative approximation subspace to compute the first eigenvalues of the vibrational Hamiltonian which are those of interest in the experimental results. In the Born Oppenheimer approximation, calling by x = (x1, . . . xN ) the dimensionless normal coordinates [4], ωi the angular frequency associated with the coordinate xi and ~ the reduced P...

Meckel's diverticulum is the most significant diverticulum occurring in the jejunum or ileum. It is a remnant of an omphalomesenteric or vitelline duct which normally obliterates at about the seventh week of foetal life (Oppenheimer, 1962). For reasons unknown, a remnant of the duct may persist, more or less completely, as a tube or cord arising usually from the ileum 25-90 cm from the ileocaec...