Lixin Lu

All Publications

• Prediction of photodynamics of 200 nm excited cyclobutanone with linear response electronic structure and ab initio multiple spawning. The Journal of chemical physics Hait, D., Lahana, D., Fajen, O. J., Paz, A. S., Unzueta, P. A., Rana, B., Lu, L., Wang, Y., Kjønstad, E. F., Koch, H., Martínez, T. J. 2024; 160 (24)

  Abstract

  Simulations of photochemical reaction dynamics have been a challenge to the theoretical chemistry community for some time. In an effort to determine the predictive character of current approaches, we predict the results of an upcoming ultrafast diffraction experiment on the photodynamics of cyclobutanone after excitation to the lowest lying Rydberg state (S2). A picosecond of nonadiabatic dynamics is described with ab initio multiple spawning. We use both time dependent density functional theory (TDDFT) and equation-of-motion coupled cluster singles and doubles (EOM-CCSD) theory for the underlying electronic structure theory. We find that the lifetime of the S2 state is more than a picosecond (with both TDDFT and EOM-CCSD). The predicted ultrafast electron diffraction spectrum exhibits numerous structural features, but weak time dependence over the course of the simulations.

  View details for DOI 10.1063/5.0203800

  View details for PubMedID 38912674

• Attosecond-pump attosecond-probe x-ray spectroscopy of liquid water. Science (New York, N.Y.) Li, S., Lu, L., Bhattacharyya, S., Pearce, C., Li, K., Nienhuis, E. T., Doumy, G., Schaller, R. D., Moeller, S., Lin, M. F., Dakovski, G., Hoffman, D. J., Garratt, D., Larsen, K. A., Koralek, J. D., Hampton, C. Y., Cesar, D., Duris, J., Zhang, Z., Sudar, N., Cryan, J. P., Marinelli, A., Li, X., Inhester, L., Santra, R., Young, L. 2024: eadn6059

  Abstract

  Attosecond-pump/attosecond-probe experiments have long been sought as the most straightforward method to observe electron dynamics in real time. Although numerous successes have been achieved with overlapped near infrared femtosecond and extreme ultraviolet attosecond pulses combined with theory, true attosecond-pump/attosecond-probe experiments have been limited. We used a synchronized attosecond x-ray pulse pair from an x-ray free electron laser to study the electronic response to valence ionization in liquid water via all x-ray attosecond transient absorption spectroscopy (AX-ATAS). Our analysis showed that the AX-ATAS response is confined to the subfemtosecond timescale, eliminating any hydrogen atom motion and demonstrating experimentally that the 1b1 splitting in the x-ray emission spectrum is related to dynamics and is not evidence for two structural motifs in ambient liquid water.

  View details for DOI 10.1126/science.adn6059

  View details for PubMedID 38359104