Protein structures are stabilized by multiple weak interactions, including the hydrophobic effect, hydrogen bonds, electrostatic effects, and van der Waals interactions. Among these interactions, the hydrogen bond is distinct in having its origins in electron delocalization. Recently, another type of electron delocalization, the n→π* interaction between carbonyl groups, has been shown to play a...

The folding of proteins is directed by a variety of interactions, including hydrogen bonding, electrostatics, van der Waals' interactions, and the hydrophobic effect. We have argued previously that an n→π* interaction between carbonyl groups be added to this list. In an n→π* interaction, the lone pair (n) of one carbonyl oxygen overlaps with the π* antibonding orbital of another carbonyl group....

We have developed an electron cloud module and implemented it in the ORBIT Code for beam dynamics in high intensity rings. In addition to studying the dynamics of the electron cloud, our intent in developing this model is to examine the effect of the electron cloud on the protons. In this presentation, we examine benchmarking and initial applications of the ORBIT electron cloud module to SNS. S...

We show that the use of the quantum theory of atoms in molecules (QTAIM) in electronically excited states allows expanding the knowledge that the molecular orbital (MO) framework provides about electronic rearrangements. Despite that historical prejudice seemed to preclude the use of QTAIM beyond the electronic ground state, this paper evidences that QTAIM is versatile enough to deal with excit...

Gas ionization and electron multiplication due to the secondary-emission process on the inner side of the beam pipe may induce the buildup of an electron cloud, which can significantly degrade the performance of rings operating with closely spaced proton or positron bunches. The undesired electron cloud causes pressure rise and beam instability when the parameters are pushed above certain thres...

Utilizing the symmetry-breaking and π-bridge-extending strategy, three non-fullerene acceptors with DA′D core unit electron-withdrawing are designed synthesized via changing alkoxy-substituted thiophene bridge unit.

The mechanism of longitudinal interaction of high-energy positrons of a bunch train and secondary emitted particles of electron cloud is analyzed. We consider the case when electron cloud in solenoidal magnetic field is built mainly due to multipacting process. Positron bunches have to use some amount of their kinetic energy to give electron cloud some temperature. The field, which is responsib...