Laser-induced dynamic alignment of the HD molecule without the Born-Oppenheimer approximation
AffiliationDepartment of Chemistry and Biochemistry, University of Arizona
MetadataShow full item record
PublisherAmerican Institute of Physics Inc.
CitationAdamowicz, L., Kvaal, S., Lasser, C., & Pedersen, T. B. (2022). Laser-induced dynamic alignment of the HD molecule without the Born-Oppenheimer approximation. Journal of Chemical Physics, 157(14).
JournalJournal of Chemical Physics
RightsCopyright © 2022 Author(s). Published under an exclusive license by AIP Publishing.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at email@example.com.
AbstractLaser-induced molecular alignment is well understood within the framework of the Born-Oppenheimer (BO) approximation. Without the BO approximation, however, the concept of molecular structure is lost, making it hard to precisely define alignment. In this work, we demonstrate the emergence of alignment from the first-ever non-BO quantum dynamics simulations, using the HD molecule exposed to ultrashort laser pulses as a few-body test case. We extract the degree of alignment from the non-BO wave function by means of an operator expressed in terms of pseudo-proton coordinates that mimics the BO-based definition of alignment. The only essential approximation, in addition to the semiclassical electric-dipole approximation for the matter-field interaction, is the choice of time-independent explicitly correlated Gaussian basis functions. We use a variational, electric-field-dependent basis-set construction procedure, which allows us to keep the basis-set dimension low while capturing the main effects of electric polarization on the nuclear and electronic degrees of freedom. The basis-set construction procedure is validated by comparing with virtually exact grid-based simulations for two one-dimensional model systems: laser-driven electron dynamics in a soft attractive Coulomb potential and nuclear rovibrational dynamics in a Morse potential. © 2022 Author(s).
Note12 month embargo; published online: 10 October 2022
VersionFinal published version