Spoilers below for Ursula Le Guin’s short story “The Ones Who Walk Away From Omelas.” If you haven’t read it, it’s short—go and do so now! TW: child abuse, suicide. In her short story “The Ones Who Walk Away From Omelas,” Ursula Le Guin describes an idyllic town (Omelas) built entirely on the misery of a single, innocent child.
Sometimes you come across a reaction which is so simple in concept that you wonder why it took so long to be accomplished in practice.
The failure of conventional calculations to handle entropy is well-documented. Entropy, which fundamentally depends on the number of microstates accesible to a system, is challenging to describe in terms of a single set of XYZ coordinates (i.e. a single microstate), and naïve approaches to computation simply disregard this important consideration.
The term bispericyclic reaction was famously coined by Caramella et a l in 2002[cite]10.1021/ja016622h[/cite] to describe the unusual features of the apparently innocuous dimerisation of cyclopentadiene. It shows features of two paths for different pericyclic reactions, comprising a 2+4 cycloaddition in the early stages, but evolving into a (degenerate) pair of [3,3] sigmatropic reactions in the latter stages.
Talent , by Tyler Cowen and Daniel Gross, is a book about talent selection—in other words, a book about hiring.
In our recently published work on screening for generality, we selected our panel of model substrates in part using cheminformatic techniques.
In the course of preparing a literature meeting on post-Hartree–Fock computational methods last year, I found myself wishing that there was a quick and simple way to illustrate the relative error of different approximations on some familiar model reactions, like a "report card" for different levels of theory.
In previously asking what the largest angle subtended at four-coordinate carbon might be, I noted that as the angle increases beyond 180°, the carbon becomes inverted, or hemispherical (all four ligands in one hemisphere). So what does a search for this situation reveal in the CSD?
Who is Peter Thiel? Tyler Cowen calls him one of the most important public intellectuals of our era. Bloomberg called him responsible for the ideology of Silicon Valley “more than any other living Silicon Valley investor or entrepreneur.” Depending on who you ask, he’s either a shadowy plutocratic genius or a visionary forward-thinking genius: but everyone seems to at least agree that he’s a genius.
Four-coordinate carbon normally adopts a tetrahedral shape, where the four angles at the carbon are all 109.47°. But how large can that angle get, and can it even get to be 180°? A search of the CSD (crystal structure database) reveals a spiropentane as having the largest such angle, VAJHAP with 164°[cite]10.1021/ja00186a058[/cite] Because crystal structures might have artefacts such as disorder etc, it is always good to check this with a