Output of a Diffractometer - Chemistry Stack Exchange The crystal on the pin (or the loop) of the goniometer head, the diffraction experiment is the gradual movement around multiple axes (or circles) to access a reasonably large portion of the reciprocal space around the crystal One of the more frequent setups is a 4-circle diffractometer (credit UPenn) With the crystal symbolized by the cube in the center you have circles $\phi$, $\omega$, $2
biochemistry - How do I interpret the results of this DNA gel . . . This run was meant to be a sort of mock-forensics experiment There is DNA from the "crime scene", "suspect 1", and "suspect 2" There are 3 samples from each, one is untreated, one is digested with EcoRV, and one is digested with PstI
Can we run PBEh-3c in Gaussian? - Chemistry Stack Exchange Can someone help with with setting up a calculation to run the new composite scheme PBEh-3c in Gaussian? The code has been implemented in Turbomole and ORCA and it's pretty easy to run it there
What causes the DNA fragments to stop moving in gel electrophoresis? Also today it is quite common to have the DNA stain already in the gel while the electrophoresis is running (instead of adding a staining solution at the end of the run) This allows to follow the DNA run in "real time"
nmr spectroscopy - Chemistry Stack Exchange This is the basis of (for example) the $\ce {D2O}$ shake test, and is also the reason why peptide protein NMR is commonly run using $90\%~\ce {H2O} 10\%~\ce {D2O}$ as a solvent (or else the NH peaks would be unobservable) What causes them to disappear from the spectrum?
nmr spectroscopy - Qualitative explanation of how COSY works . . . 2D experiments are measured much in the same way, except instead of running the pulse sequence once, we run it multiple times, changing some variable and collecting all of the data into one set which will later become the 2D spectrum [*] The standard COSY experiment is one of the simplest 2D experiments to understand
Convergence issue in Gaussian - Chemistry Stack Exchange Just few suggestions for finding a stationary point You can add some additional angular flexibility into the basis by changing it to, say, 6-31G(2df,p) or even switch to more modern Ahlrichs' def2 bases (Def2SVP to start from) Besides, you'd better use UltraFine integration grid and tight optimization criteria and do geometry optimization and frequency calculation in a single run: Opt=Tight
Why is the Haber process carried out at such high temperatures? As others have pointed out, it is purely kinetics, but you may still wonder, why For a reaction to actually occur (in both directions) and thus for an equilibrium to be reached, you need to overcome the activation energy In the case of the Haber-Bosch process, this involves breaking the highly stable $\ce {N#N}$ triple bond Even with the catalysts used, the energy required to break apart
Is water a possible fuel for jet engines? [closed] Jet engines can run on almost any fuel, and the operating temperatures of modern jet engines' hottest sections are anywhere between 3000 and 3150 degrees F (1648 and 1732 degrees Celsius) Does tha