Output of a Diffractometer - Chemistry Stack Exchange
网页2024年8月15日 · Its purpose is to translate from coordinate system of the reciprocal space (a∗,b∗,c∗) (a ∗, b ∗, c ∗) into the cartesien (x, y, z) (x, y, z) of the diffractometer. The former may be oblique because (a, b, c) (a, b, c) in the rhombohedral, hexagonal, monoclinic, triclinic crystal system enclose at least one angle which is not ...
What are the maximum number of electrons in each shell?
网页2014年2月20日 · In the third shell (n=3), we have: The 3s orbital; The 3p orbitals; The 3d orbitals; In the fourth shell (n=4), we have: The 4s orbital; The 4p orbitals; The 4d orbitals; The 4f orbitals; So another kind of orbitals (s, p, d, f) becomes available as we go to a shell with higher n. The number in front of the letter signifies which shell the ...
Convergence issue in Gaussian - Chemistry Stack Exchange
网页2016年8月29日 · 1. Generally, you need all the 4 parameters to converge. However, displacement values may be large unrelated to the question wheater your geometry is stationary or not. It is a judgement call and you should have your chemical insight into the system to see wheater these values raise a red flag or not. – Greg.
computational chemistry - When using Gaussian to calculate NMR, …
网页2014年7月29日 · Run an NMR single-point calculation with the following route section in GAUSSIAN. #n B3LYP/6-31G(d,p) nmr=(fconly,readatoms) iop(3/10=1100000) At the end of the molecule specification (separated by a blank line) read in: atoms=H. A sample input file for chloroethane could be like:
How can I filtrate Pd2(dba)3 and P(o-tol)3? (Celite filtration failed)
网页2021年6月21日 · Reaction solvent is toluene in which the catalysts also dissolve. Many texts said that celite pad can filtrate these catalysts, but I failed. I tried vacuum filtration using buchner filter, and poured $\pu{0.0087 g}$ $\ce{Pd2(dba)3}$ in $\approx \pu{25 mL}$ toluene. $\ce{Pd2(dba)3}$ in toluene has dark red color, but filtrate also has same ...
How to calculate the amount of gas in a compressed cylinder
网页2015年4月15日 · Gas used CP-grade N2 material number: 110628-L can. Gas: N, density = 1.251 g/L @ 0.101 MPa M (molar mas) = 14.007. Gas cylinder: Pressure = 200 bar or 20 MPa Cylinder volume 9.45 m3 or 9450 L. Operating pressure of gas from cylinder = 4.5 bar or 0.45 MPa and flow rate = 60 cL/min. I have been applying the ideal gas law to …
kinetics - Calculation of the specific rate constant (k) - Chemistry ...
网页2014年2月26日 · We assume 1 order kinetics in hypochlorite and 1 order kinetics in the color. Putting this in the equation we get the following: d[Red] dt = −k[Red [bleach d [Red] d t = − k [Red] [bleach] Because you keep the concentration of bleach the same throughout the trial, you can write. kobs = k × [bleach] k obs = k × [bleach]
How to run a B2PLYP-D3 calculation in Gaussian 09?
网页2017年1月19日 · %nprocshared=4 %mem=4gb %chk=fohsdft3 # opt freq b2plypd3/aug-cc-pvdz scf=tight Input file taken from fohsdft 0 1 O -3.46278 2.54045 0. H -2.50278 2.54045 0. H -3.78324 3.44539 0. Since B2PLYP-D3 is a method, it goes where the density functional is normally specified.
Why is the Haber process carried out at such high temperatures?
网页Even if you consider a batch-wise process of generating ammonia (which, as orthocresol points out, isn’t the case), it is more efficient to run two batches in half the time for two sets of $15~\%$ than to run a single batch for twice the time to get an overall yield of maybe (note: This yield is a ballpark estimate) $25~\%$ — with a batch ...
What causes the DNA fragments to stop moving in gel …
网页2012年5月25日 · $\begingroup$ 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". $\endgroup$ –