# Invariant exchange perturbation theory for multicenter systems: Time-dependent perturbations

## Abstract

A formalism of exchange perturbation theory (EPT) is developed for the case of interactions that explicitly depend on time. Corrections to the wave function obtained in any order of perturbation theory and represented in an invariant form include exchange contributions due to intercenter electron permutations in complex multicenter systems. For collisions of atomic systems with an arbitrary type of interaction, general expressions are obtained for the transfer (T) and scattering (S) matrices in which intercenter electron permutations between overlapping nonorthogonal states belonging to different centers (atoms) are consistently taken into account. The problem of collision of alpha particles with lithium atoms accompanied by the redistribution of electrons between centers is considered. The differential and total charge-exchange cross sections of lithium are calculated.

- Authors:

- St. Petersburg State Technical University (Russian Federation)

- Publication Date:

- OSTI Identifier:
- 22472387

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Journal of Experimental and Theoretical Physics; Journal Volume: 120; Journal Issue: 2; Other Information: Copyright (c) 2015 Pleiades Publishing, Inc.; Country of input: International Atomic Energy Agency (IAEA)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 74 ATOMIC AND MOLECULAR PHYSICS; ALPHA PARTICLES; ATOMS; CHARGE EXCHANGE; CORRECTIONS; CROSS SECTIONS; ELECTRONS; ION-ATOM COLLISIONS; LITHIUM; PERTURBATION THEORY; S MATRIX; SCATTERING; TIME DEPENDENCE; WAVE FUNCTIONS

### Citation Formats

```
Orlenko, E. V., E-mail: eorlenko@mail.ru, Evstafev, A. V., and Orlenko, F. E.
```*Invariant exchange perturbation theory for multicenter systems: Time-dependent perturbations*. United States: N. p., 2015.
Web. doi:10.1134/S106377611502017X.

```
Orlenko, E. V., E-mail: eorlenko@mail.ru, Evstafev, A. V., & Orlenko, F. E.
```*Invariant exchange perturbation theory for multicenter systems: Time-dependent perturbations*. United States. doi:10.1134/S106377611502017X.

```
Orlenko, E. V., E-mail: eorlenko@mail.ru, Evstafev, A. V., and Orlenko, F. E. Sun .
"Invariant exchange perturbation theory for multicenter systems: Time-dependent perturbations". United States.
doi:10.1134/S106377611502017X.
```

```
@article{osti_22472387,
```

title = {Invariant exchange perturbation theory for multicenter systems: Time-dependent perturbations},

author = {Orlenko, E. V., E-mail: eorlenko@mail.ru and Evstafev, A. V. and Orlenko, F. E.},

abstractNote = {A formalism of exchange perturbation theory (EPT) is developed for the case of interactions that explicitly depend on time. Corrections to the wave function obtained in any order of perturbation theory and represented in an invariant form include exchange contributions due to intercenter electron permutations in complex multicenter systems. For collisions of atomic systems with an arbitrary type of interaction, general expressions are obtained for the transfer (T) and scattering (S) matrices in which intercenter electron permutations between overlapping nonorthogonal states belonging to different centers (atoms) are consistently taken into account. The problem of collision of alpha particles with lithium atoms accompanied by the redistribution of electrons between centers is considered. The differential and total charge-exchange cross sections of lithium are calculated.},

doi = {10.1134/S106377611502017X},

journal = {Journal of Experimental and Theoretical Physics},

number = 2,

volume = 120,

place = {United States},

year = {Sun Feb 15 00:00:00 EST 2015},

month = {Sun Feb 15 00:00:00 EST 2015}

}