Hellmann-Feynman theorem and the definition of forces in quantum time-dependent and transport problems
- Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235 (United States)
The conventional Hellmann-Feynman theorem for the definition of forces on nuclei is not directly applicable to quantum time-dependent and transport problems. We present a rigorous derivation of a general Hellmann-Feynman-like theorem that applies to all quantum mechanical systems and reduces to well-known results for ground-state problems. It provides a rigorous definition of forces in time-dependent and transport problems. Explicit forms of Pulay-like forces are derived and the conditions for them to be zero are identified. A practical scheme for ab initio calculations of current-induced forces is described and the study of the transfer of a Si atom between two electrodes is presented as an example. (c) 2000 The American Physical Society.
- OSTI ID:
- 20216791
- Journal Information:
- Physical Review. B, Condensed Matter and Materials Physics, Vol. 61, Issue 23; Other Information: PBD: 15 Jun 2000; ISSN 1098-0121
- Country of Publication:
- United States
- Language:
- English
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