Brorsen Lab

Now for a post over a very different topic than is usual.

Our group has assisted in a new study led by the Young group in Chemical Engineering here at Mizzou on redox-active amine polymers. The paper is largely experimental, but Naresh played an important role by performing DFT calculations to find the barrier to nitrate ion transport through polypyrrole films.

You can check out the paper here: https://doi.org/10.1021/acs.chemmater.2c02225 .

Lots of exciting news that I have been negligent in posting.

A new gradate student, Yussuf Fasasi, has joined the group! He is going to be working in collaboration with the Young group in ChemE on performing simulations of ion insertion in thin-film materials.

Irina has been selected for an REU at Vanderbilt University for the summer. She’ll be working on performing machine-learning calculations to estimate docking scores for medicinal chemistry. There is a real chance given my meager knowledge of biology/biochemistry there is something not 100% correct in the previous sentence.

Lastly, Dylan has been named a Cherng Summer Scholar here at Mizzou, which means he will be able to perform research with the group all summer. On the topic of Dylan’s research, we hope to have an exciting followup by the end of the summer.

With the new semester starting, we also have two new group members.

The first is Gabrielle Tucker, who is starting graduate school this spring. Gabbie worked with us this summer as a Steven’s Scholar and has decided to return on a more permanent basis!

The second is Dylan Fowler. Dylan is a sophomore undergrad in the chemistry department here at Mizzou. Dylan actually started with us in September of last year, but, as I neglected many things last fall due to teaching General Chemistry, I never got the website updated.

Both of them are working on various aspects of multicomponent many-body methods by extending and/or improving Jonathan’s multicomponent CCSD code (which you can now find an alpha version of listed under the “code” section!).

Welcome to them both.

Two posts in one day!?!

Jonathan’s paper has also been published in JCP (directly after Naresh’s!). In this paper, we derive the full multicomponent MP3 and MP4 equations for the first time. Multicomponent MP4 performs surprising well considering the well known failures of multicomponent HF. This paper is also the first time any connected triple-excitation contribution has been included in a many-body multicomponent method and these triple excitations are shown to increase the accuracy of proton affinities significantly.

Kurt did most of the derivations of this paper, while Jonathan did the herculean job of coding it all up. The reason I (Kurt) mention this is that I can still remember being a sophomore undergraduate just starting research and being handed a copy of Szabo and Ostlund and thinking the Hugenholtz and Goldstone diagrams in it and on the cover were the COOLEST thing ever (not that I understood them until a few years ago). While I may no longer think they are the “coolest thing ever,” I still am pretty happy in a silly way that this is the first paper I have been a part of that has made use of them.

Link is here: https://doi.org/10.1063/5.0071423

It has been a while since we have had a post on the group website. Part of the reason for this is that Kurt has been teaching General Chemistry for the first time this semester (his review of the experience: lots of work, but fun otherwise).

But while he was doing that, the rest of the group continued working hard. Today, Naresh’s first paper in the group was published in JCP! In this paper, Naresh takes our previous implementation of multicomponent HBCI and (1) extends it to excited states and (2) implements the perturbative energy correction. Both of these are important extensions for a fully featured multicomponent HBCI method and appear to perform well.

Kurt also added some results to the study about how to best benchmark multicomponent methods for excited states using FGH. He has had these ideas since at least his first semester at Mizzou. Basically, in order to get appropriate FGH reference results you need to restrain the electronic basis to not follow the quantized particle when performing FGH.

Link to paper: https://doi.org/10.1063/5.0076006