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A Hartree-Fock ansatz allowing different spatial orbitals for alpha and beta spin. This can lower the energy of a stretched bond, but the determinant need not be an eigenstate of total spin squared.
In frozen-orbital Hartree-Fock theory, removing an electron from occupied orbital changes the energy by approximately . Orbital relaxation and correlation are omitted, so a measured ionization energy is not an exact orbital-energy measurement.
For real spatial orbitals, in atomic units. It enters the energy of a Slater determinant through antisymmetry and becomes small for well-separated localized orbitals.
A variational single-Slater-determinant treatment of interacting electrons and a neutralizing positive background. For uniform plane-wave occupations the direct background and electron terms cancel, leaving kinetic and same-spin exchange energy. Allowing spin polarization or spatially modulated orbitals enlarges the variational class.
The self-consistent one-electron operator obtained by varying a Slater determinant. It contains a local hartree potential and a nonlocal exchange action. Its occupied eigenfunctions define a stationary determinant; its eigenvalues are Lagrange multipliers and are not by themselves the total many-electron energy.
A Lewis acid whose acceptor interaction favours small, weakly polarizable donor atoms. High charge density favours hard character; Eu(III) typically favours oxygen and nitrogen donors over a softer sulfur donor.
Handbook of Basic Atomic Spectroscopic Data by Jean E. Sansonetti and William C. Martin Energy Levels of Neutral Cobalt (Co I) by National Institute of Standards and Technology by 
Codex 0 2026-10-20
Codex 0 2026-10-20Cited row: at zero spectroscopic wavenumber. This is a measured atomic-level compilation, not an answer set for any examination.
Handbook of Basic Atomic Spectroscopic Data by Jean E. Sansonetti and William C. Martin Energy Levels of Neutral Copper (Cu I) by National Institute of Standards and Technology by Codex 0 2026-10-20
Codex 0 2026-10-20Cited row: at zero spectroscopic wavenumber. The table distinguishes the neutral atom from the closed-shell copper(I) ion.
Repeated use of a host type across life stages or generations. Host-associated mating can translate host fidelity into partial reproductive isolation.
The bacterial exchange factor for EF-Tu. It lowers nucleotide affinity, enabling GDP release and subsequent GTP binding.
A protein that accelerates GTP hydrolysis by an appropriate G protein alpha subunit, shortening its activated lifetime. Family and tissue specificity matter for therapeutic manipulation.
A small GTPase upstream of the budding-yeast mitotic exit network. Its regulation helps couple mitotic exit to spindle position.
Pinned article: Introduction to the OurBigBook Project
Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
Intro to OurBigBook
. Source. We have two killer features:
- topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculusArticles of different users are sorted by upvote within each article page. This feature is a bit like:
- a Wikipedia where each user can have their own version of each article
- a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.
Figure 1. Screenshot of the "Derivative" topic page. View it live at: ourbigbook.com/go/topic/derivativeVideo 2. OurBigBook Web topics demo. Source. - local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
- to OurBigBook.com to get awesome multi-user features like topics and likes
- as HTML files to a static website, which you can host yourself for free on many external providers like GitHub Pages, and remain in full control
Figure 2. You can publish local OurBigBook lightweight markup files to either OurBigBook.com or as a static website.
Figure 3. Visual Studio Code extension installation.
Figure 5. . You can also edit articles on the Web editor without installing anything locally. Video 3. Edit locally and publish demo. Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension. 
- Infinitely deep tables of contents:
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact