Category: Publications

May 15, 2017

Paper on Excited State Raman is now online

Time-resolved Raman spectroscopy has proven useful for studying the formation of polarons in conjugated polymers, verifying the presence of reactive intermediates in photochemical reactions, investigating nonradiative transitions in the short lifetime of the photoexcited species, and resolving electron−phonon coupling strengths and exciton dissociation in crystalline materials. We extended the recently published transient vibrational analysis to […]


May 15, 2017

Vibrational Perturbation Theory with TDDFT Paper is now online

With the recent (yet to be published) work by us and collaborators at Gaussian on the efficient implementation of the analytic TDDFT energy Hessians, it is possible to perform calculations of excited-state infrared spectra of medium-large isolated molecular systems, with anharmonicity effects included in both the energy and property surfaces. We also explore the use […]


March 28, 2017

Probing Curiously Long-Lived Coherent States in Bimetallic Pt (II) Clusters

Coherence between electronic states occurs when at least two time-evolving eigenstates form a superposition state by linear combination and the frequencies of the two states feature a constant phase difference. The simplest representation is the coherence between two eigenstates although in principle an infinite number of states may be in coherent superposition. However, an event […]


December 7, 2016

Can Quantized Vibrational Effects be Obtained from Ehrenfest Mixed Quantum-Classical Dynamics?

An interesting question is whether or not mean-field or “Ehrenfest” mixed quantum-classical dynamics can capture the quantized vibrational features in photoabsorption spectra that result from infrared and Raman-active vibrational transitions. We show that vibrational and electronic absorption spectra can be obtained together within a single Ehrenfest simulation. The electronic transitions show new sidebands that are […]


November 1, 2016

Ab Initio Transient Vibrational Spectral Analysis

Pump probe spectroscopy techniques have enabled the direct observation of a variety of transient molecular species in both ground and excited electronic states. Time-resolved vibrational spectroscopy is becoming an indispensable tool for investigating photoinduced nuclear dynamics of chemical systems of all kinds. We developed a transient vibrational analysis protocol combining ab initio direct molecular dynamics […]