Computational Chemistry 4.8 - Excited Determinants HD

Short lecture on excited Slater determinants for N-electron wavefunctions. A ground state Slater determinant contains all N electrons of a molecular system in the N spin orbitals with the lowest possible energy (i.e. it follows the aufbau principle). An excited Slater determinant contains at least one electron which does not occupy the lowest energy spin-orbital available to it. In a system with K atomic orbital basis functions, the are 2K total spin orbitals (K alpha [spin up] and K beta [spin down]). This means that any Slater determinant has N occupied and 2K-N virtual (unoccupied) spin orbitals, meaning that even for a modest number of basis functions there are an enormous (exponential) number of possible excited state determinants due to this combinatoric explosion. One excited electron is a singly excited determinant; doubly for two; triply for three, etc. Notes Slide: https://i.imgur.com/4GVKSuD.png --- About TMP Chem --- All TMP Chem content is free for everyone, everywhere, and created independently by Trent Parker. Email: tmpchemistry@gmail.com --- Video Links --- Course Playlist: https://www.youtube.com/playlist?list=PLm8ZSArAXicIWTHEWgHG5mDr8YbrdcN1K Chapter Playlist: https://www.youtube.com/playlist?list=PLm8ZSArAXicIijiVIx0yfk2ZOK-16ycji Other Courses: https://www.youtube.com/playlist?list=PLm8ZSArAXicIXArfap9Tcb8izqRPvE0BK Channel Info: https://www.youtube.com/playlist?list=PLm8ZSArAXicLlGO4Rvpz-D6vX8MFbOn4V --- Social Links --- Facebook: https://www.facebook.com/tmpchem Twitter: https://www.twitter.com/tmpchem LinkedIn: https://www.linkedin.com/in/tmpchem Imgur: https://tmpchem.imgur.com GitHub: https://www.github.com/tmpchem --- Equipment --- Microphone: Blue Yeti USB Microphone Drawing Tablet: Wacom Intuos Pen and Touch Small Drawing Program: Autodesk Sketchbook Express Screen Capture: Corel Visual Studio Pro X8