Synthetic inorganic chemistry group @PennChemistry. Ln/An. Structure, bonding, reactivity, separations, catalysis. Always retweets xtal pics.

Joined July 2015
247 Photos and videos
SchelterGroup retweeted
If you want relationship advice, look towards semiconductors. A semiconductor without defects is a rock, useless. Put in a small number of defects and it conducts electricity better, but still not useful. But when you put two different semiconductors together (either different doping type or different band gap) and their Fermi levels align, this is where the magic happens--diodes, 2DEGs. The basis of useful semiconductor devices is the defects and the interfaces.
13
24
199
10,487
SchelterGroup retweeted
Love em physics memes!
1
7
70
2,323
SchelterGroup retweeted
Comparison of Bonding in Isostructural Cerium and Thorium Parent Amide Complexes | Inorganic Chemistry pubs.acs.org/doi/10.1021/acs… Autschbach, Schelter, and co-workers @InorgChem #cerium #thorium #amide #DFT #15NNMR
8
24
1,308
SchelterGroup retweeted
🌻The “God of #Fluorine,” Karl Otto Christe, passed away on April 19, 2026, in California. He was born in Ulm, Germany, and studied chemistry at the University of Stuttgart @Uni_Stuttgart from 1957 onwards. He received his PhD in 1961 for work with Josef Goubeau and emigrated to California a year later. There he worked first for #Stauffer Chemical Co. and from 1967–1994 for Rockwell International, a company well known for producing rocket fuels. From 1994–2005, Christe was a Senior Staff Advisor at the Air Force Research Laboratory of Edwards Air Force Base @AFResearchLab, and in parallel he was a Professor at the Loker Hydrocarbon Research Institute of the University of Southern California @UniversityofSo5. Christe was most famous for the first completely chemical synthesis of elemental fluorine. Furthermore, he synthesized iconic ions like NF₄⁺ and ClF₆⁺ as well as extremely reactive polynitrogen ions like the linear-angled N₅⁺ and the cyclic N₅⁻, and he was well known as an expert in #EnergeticMaterials. He received the “Apollo Achievement Award” for his contributions to the Apollo missions and a wide range of prizes from the ACS @AmerChemSociety, the #SFC, and the GDCh @GDCh_aktuell. Christe’s contributions to inorganic chemistry cannot be overestimated.
2
5
26
1,602
SchelterGroup retweeted
The Booker Lab at the University of Pennsylvania, in Philadelphia, and HHMI is searching for a lab manager. If interested, please apply at the HHMI link below.hhmi.wd1.myworkdayjobs.com/e…

5
27
51
9,104
SchelterGroup retweeted
There’s an unlikely and little-known connection between NASA’s Artemis II lunar mission and one of Hans Bethe’s most practical yet least celebrated contributions from the late 1950s. While consulting for AVCO on ICBM reentry vehicles, the Nobel laureate teamed up with engineer Mac Adams to publish a landmark 1959 paper: “A Theory for the Ablation of Glassy Materials.” The problem they tackled seemed almost impossible at the time: a nose cone slamming back into the atmosphere at Mach 25 would be enveloped in plasma hotter than 5,000 °F. Any normal material would simply vaporize. Pure insulation wouldn’t work; it would have to be impractically thick. Bethe and Adams realized the solution wasn’t to resist the heat but to embrace controlled sacrifice. They focused on glassy materials like fused quartz and glass-phenolic composites that would melt rather than char or burn chaotically. Here’s what their theory showed: The outer surface reaches melting point and forms a thin, viscous liquid film. The hypersonic airflow shears this molten layer away, blowing it off as gas and droplets. The energy is carried outward and is absorbed in melting, vaporization, and convection instead of conducting inward. The ablation front steadily recedes, layer by layer, but the solid material behind it stays near room temperature. A shield only about an inch thick is enough. It was active cooling by mass loss, not passive protection. The heat shield literally burns away, turning the incoming plasma’s fury into exhaust that protects the vehicle. That same foundational physics underpins today’s Orion capsule heat shield for Artemis II. Orion uses Avcoat - the only difference being that it is a charring ablator instead of a melting, glassy one, but descended from the same principles. The outer blocks pyrolyze and char at thousands of degrees, releasing gases that block the plasma and carry heat away, while the interior stays cool enough for the crew. So when you watch Orion plunge through the atmosphere at 25,000 mph with its glowing plasma sheath, you’re seeing 1950s nuclear-missile research - refined by one of the 20th century’s greatest theoretical physicists - still keeping astronauts safe on the way back from the Moon. ICBM tech to lunar return. Science really is the ultimate long-term investment.
Look at this astronaut's face during reentry, knowing the capsule exterior is at 5,000°F. The physics of why he's alive are wild. The air in front of the capsule compresses so violently at Mach 25 that it turns into plasma. 5,000°F on the surface. Half the temperature of the sun. The heat shield absorbs that energy by literally burning itself away, layer by layer, carrying the heat with it as gas. One inch of material is the entire margin. On the outside of that inch: 5,000°F. On the inside: 75°F. Room temperature. The thermal gradient across that single inch is the steepest temperature drop humans have ever engineered. The orange glow in the window is ionized nitrogen and oxygen. That plasma is why comms go black for six minutes during reentry. Ground control can't reach the crew. The astronauts are alone inside a fireball, falling at 25,000 mph, watching the laws of thermodynamics keep them alive through a 1-inch wall. Artemis II did exactly this last night. Four astronauts hit Earth's atmosphere at 24,664 mph, rode a 4,900°F plasma sheath for six minutes of radio silence, and splashed down a mile from target. The heat shield is now being inspected for cracks. They found over 100 on the last unmanned test.
3
37
151
10,644
SchelterGroup retweeted
Join us next week, March 31, 12 pm ET for excellent talks from Prof. Jason Khoury (@ASU_SMS) & Prof. Stephen Liddle (@OfficialUoM)! Reg: Email Prof Robinson! #fblock #chemtwitter @InorgChem @DaltonTrans @EurJIC @InorgChemFront @ACSINORDivision @NSF @doescience
4
12
1,113
SchelterGroup retweeted
I'm finalizing one grant application this week. I'm writing it without any AI assistance despite temptations. One reason is that writing grants used to be an integral part of the creative process, so I would let evolve ideas and understand myself better what I want to discover.
2
1
38
2,060
SchelterGroup retweeted
Annual reminder: if you’ve been accepted to multiple graduate programs and are still deciding, please let the ones you’re definitely not going to know as soon as possible! -Someone who got into his PhD off the waitlist the day after the deadline
1
25
219
14,941
SchelterGroup retweeted
Remember when MOOCs were going to make universities obsolete?
This is crazy .... but I said it before, and I'll say it again. AI has now made college degrees earned through online education worthless.
5
7
86
7,042
SchelterGroup retweeted
Congrats! You’ve completed the seventh round of revisions. Just one more round of reviews and then we’ll let you know if your paper has been accepted.

2
4
23
1,683
SchelterGroup retweeted
I would like to thank @berachm who encouraged me to switch field from transition metals to rare earths and @SchelterGroup who first introduced me to f- element chemistry. They made me realize that Rare earths are future for science!! Looking forward to explore REE chemistry now!!
1
2
36
3,546
SchelterGroup retweeted
Happy to share that I have joined @iitjodhpur as Assistant Professor of Chemistry. My heartfelt gratitude to my Ph.D supervisor @berachm, postdoctoral supervisors @SchelterGroup, and Prof.Marinella Mazzanti for their guidance support and motivation throughout my academic journey!
22
4
267
12,469
SchelterGroup retweeted
The first material to superconduct above liquid nitrogen temperature was YBa2Cu3O7 (YBCO), and it is still the workhorse behind most high-Tc ‘products.’ A tale related to the publication of its discovery in the late 1980s, probably apocryphal, is as follows. The authors submitted the results for peer review–Tc up to 93K, unfathomable just a year prior. Because of the highly charged atmosphere around high-Tc at that time, in the version they sent for peer review, they said that the compound was made with Ytterbium (Yb) not Yttrium (Y). At the proofs stage they were like ‘oopsie!’ and corrected to composition. According to lore, this caused global Ytterbium prices to spike.
3
4
44
4,365
SchelterGroup retweeted
Agentic AI and rare-earth minerals have been trending lately. In our latest paper in @J_A_C_S , we describe an open-source agentic workflow for designing new rare earth and actinide separations... pubs.acs.org/doi/10.1021/jac…
2
6
24
5,379
SchelterGroup retweeted
, Inorganic Chemistry Gordon Research Conference (and Graduate Research Seminar) #GRC #InorganicGRC May 31st - June 5th, 2026 (May 30th - May 31st for the GRS!) at Salve Regina in Newport, RI photo cortesy of @BuddhimaMaldeni
1
1
25
1,860
SchelterGroup retweeted
When things are feeling really bad I watch this video. I believe it is the most important video on the internet.
379
20,986
101,765
6,162,971
SchelterGroup retweeted
Additional single crystals have been synthesized for centralized structural analysis soon. Having characterized numerous samples this year, I expect these latest crystals to yield noteworthy results.#MOFs #SingleCrystal
1
34
1,736
SchelterGroup retweeted
Excited states are fleeting and every photochemical reaction is a race against time. Photochemists live on a different timescale! A beautifully designed slide from Professor Toldo illustrates this very well. Notice that the unit of time is not second but femtosecond! At @icesaa4
3
19
1,434