Check out Garrett’s new paper on incorporating norm-preserving interpolation into spawning dynamics.  Garrett shows that our wave function interpolation scheme allows the accurate calculation of population transfer probabilities even when the coupling between states varies on time scales much shorter than the integration time step.

Check out Yinan’s newest paper in J. Chem. Phys, which describes our evolutionary approach to the design of fluorophores for light emitting diodes.  We identify several classes of molecules which are predicted to have a high propensity for thermally activated delayed fluorescence, and also demonstrate our genetic algorithm approach to provide an efficient sampling of chemical space.

Yinan’s newest paper on conical intersections which arise upon oxidation of the silicon surface is in J. Phys. Chem. C.!  We show that several different silicon epoxide defects exhibit low-lying intersections, and suggest routes to experimental confirmation of these predictions.  Check it out!

What better way to ring in the new year than to read about electronic structure theory!  Check out Yinan’s new paper in JCP on a novel multireference electronic structure approach for excited states: the CISNO-CASCI method.  CISNO-CASCI is more computationally efficient than traditional state averaged (SA-) CASSCF, and unlike SA-CASSCF it provides size intensive vertical excitation energies, making it well suited for nanoscale systems composed of multiple excitable subsystems.  Enjoy!

Update:  We’re on the cover!

Yinan and I recently collaborated with the group of Marcos Dantus and Ned Jackson to study the ionization of polyatomic molecules in strong laser fields.  Together, we find that seemingly similar organic molecules (ortho/meta/para isomers of methyl acetophenone, for example) can behave very differently under strong laser fields, and that these differences in behavior can be explained if we hypothesize that, even under strong field conditions, ionization leaves behind a relatively cold ion in its electronic ground state.  In fact, small energetic differences attributable to positional isomerism are still at work even at >10^13 W / cm^2!  Check it out.

Our paper with the Lunt group is on the cover of the most recent issue of Advanced Optical Materials.  That TLSC sure is transparent!

Take a look at Garrett’s new paper on norm-preserving interpolation (NPI), our new scheme for computing time-derivative couplings.  NPI is designed to allow accurate integration of the time-dependent Schrodinger equation in spawning and surface hopping simulations even when the nonadiabatic coupling spikes on a timescale shorter than the simulation time step.  It is easy to implement and does not require analytic calculations of the non-adiabatic coupling matrix elements.

Check out our work with the group of Richard Lunt of the MSU Chemical Engineering Department in our new paper in Advanced Optical Materials.  With the goal of using windows for solar energy conversion, Richard’s group has developed devices which are nearly perfectly transparent to visible light, but use IR absorbing/emitting chromophores to concentrate light on photovoltaic cells around the edge of the device.  Our calculations point towards ways to optimize the chromophores for larger devices by minimizing reabsorption losses.

Check out Yinan’s new paper in JPC C on the photodynamics of silicon-oxygen double (Si=O) bonds.  Though Si=O defects have previously been hypothesized to be the source of the photoluminescence of oxidized silicon nanocrystals, we show that excited Si=O bonds can undergo efficient non-radiative decay via conical intersection on timescales shorter than the experimental lifetime.

Check out Garrett’s paper in J. Phys. Chem. C, which describes the theoretical prediction of an unusual mechanism for polaron formation in graphitic carbon nitrides, a class of metal-free photocatalysts.  This work was done in collaboration with Andrew Baczewski at Sandia National Lab.  Congrats to Garrett and former summer student Dan Little (currently of the Hamann group) on their first scientific paper!