The ability to locate minima on electronic excited states (ESs) potential energy surfaces (PESs) both in the case of bright and dark states is crucial for a full understanding of photochemical reactions. This task has become a standard practice for small- to medium-sized organic chromophores thanks to the constant developments in the field of computational photochemistry. However, this remains a very challenging effort when it comes to the optimization of ESs of transition metal co
mplexes (TMCs), not only due to the presence of several electronic excited states close in energy, but also due to the complex nature of the excited states involved. In this article, we present a simple yet powerful method to follow an excited state of interest during a structural optimization in the case of TMC, based on the use of a compact hole-particle representation of the electronic transition, namely the natural transition orbitals (NTOs). State t...
The RNA virus Influenza A is a serious public health problem with every year
epidemics resulting in more than 250,000 deaths. A protein cavity was identified
on the HA2 subunit of the hemagglutinin responsible for the entry of the virus into
the host cell by endocytosis. The binding of a ligand in this zone rich in invariant
residues and synthetic lethal couples, could prevent therapeutic escape and inhibit the
conformational change at pH=5 initiating the membrane fusion in the endosome. Two
pentapeptides, a linear peptide (EQRRS) and a cyclic peptide (DQRRD) have been
proposed as potential ligands. Complex stability and the interactions between the
ligand and the protein have been studied with the help of molecular dynamics and
quantum chemistry methods. A high stability of the interactions has been obtained
for these two ligands at both pH=7 and pH=5. Indeed, these two peptides present
two cooperative modes of actio...