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.