Effective potential energy curves of H₂ molecule evolving in a strong time‐dependent magnetic field

Abstract

Evolution of hydrogen molecule, starting initially from its field-free ground state, in a time-dependent (TD) magnetic field of order 10 11 G is presented in a parallel internuclear axis and magnetic field-axis configuration. Effective potential energy curves (EPECs), in terms of exchange and correlation energy, of the hydrogen molecule as a function of TD magnetic-field strength, are analyzed through TD density functional computations based on a quantum fluid dynamics approach. The numerical computations are performed for internuclear separation R ranging from 0.1 to 14.0 a.u. The EPECs exhibit field-dependent significant potential-well minima both at large internuclear separations and at short internuclear separations with a considerable increase in the exchange and correlation energy of the hydrogen molecule. The results, when compared with the time-independent (TI) studies involving static TI magnetic fields, reveal TD behavior of field-dependent crossovers between different spin-states of hydrogen molecule as indicated by the TI investigations in static magnetic fields. Besides this, present work reveals interesting dynamics in the TD total-electronic charge-density distribution of the hydrogen molecule.For a TD magnetic field B(t) applied along thẽ z direction on a cylindrical grid, the GNLSE [Eq. (11)], for a molecular system starting initially (at t VIKAS 3138 INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY

Current‐density functional study of the HeH+ molecular ion under a strong ultrashort magnetic field

“…For example, our study on the H 2 molecule reveals interesting dynamics on the attosecond time scale in the electronic charge‐density of the H 2 molecule 15. The study also revealed distinct features in the effective potential energy curves of the H 2 molecule that can have field‐dependent multiple potential‐well minima 16. However, these TD‐DFT studies employ scalar exchange–correlation (XC) potential and XC energy‐density functional, which depend only on the electronic charge‐density, whereas in the presence of even a weak magnetic field, strong currents are induced to the exposed system.…”

“…In our previous studies based on quantum fluid dynamics (QFD)17, 18 and TD‐DFT, we have investigated the He atom13, 14 and the H 2 molecule15, 16 in a strong TD magnetic field on the order of 10 9 G. These studies reveal not only key similarities with the TI studies but also surprising dynamical features which are not predicted by the TI investigations in static magnetic fields. For example, our study on the H 2 molecule reveals interesting dynamics on the attosecond time scale in the electronic charge‐density of the H 2 molecule 15.…”

“…However, all these studies in the literature that we are aware of, are carried out on the atomic and molecular systems exposed to strong static time‐independent (TI) magnetic fields. The investigation of molecules subjected to a strong TD magnetic field on the order of 10 9 G can reveal several other interesting features13–16 in the dynamics of the molecules that cannot be visualized from TI investigations involving static magnetic fields.…”

He molecular ion in a strong time‐dependent magnetic field: A current‐density functional study

“…7 All these methods have been used to study various atomic and molecular systems in strong and superstrong magnetic fields (of the order of 10 13 G), however, only for static time-independent (TI) magnetic fields. Recently, we had carried out studies [8][9][10][11] of atomic and molecular systems in presence of a strong TD magnetic field that revealed a few interesting features in the dynamics of the studied systems, which cannot be predicted using TI investigations involving static magnetic fields. For example, our study 11 of the H 2 molecule in a strong TD magnetic field of the order of 10 9 G, through a TD-DFT and quantum fluid dynamics (QFD) [12][13][14] based approach, predicted a significant feature in the effective potential energy curves that show field-dependent multiple potential-well minima.…”

“…Recently, we had carried out studies [8][9][10][11] of atomic and molecular systems in presence of a strong TD magnetic field that revealed a few interesting features in the dynamics of the studied systems, which cannot be predicted using TI investigations involving static magnetic fields. For example, our study 11 of the H 2 molecule in a strong TD magnetic field of the order of 10 9 G, through a TD-DFT and quantum fluid dynamics (QFD) [12][13][14] based approach, predicted a significant feature in the effective potential energy curves that show field-dependent multiple potential-well minima. However, these studies based on the TD-DFT did not use any current-density dependent exchange-correlation (XC) potential and XC energy density functional, whereas even in a weak magnetic field, strong currents can build up in the exposed system.…”