Two figures in, a clear answer out. The diffusion coefficient calculator uses boltzmann’s constant, radius (a), major axis (a), minor axis (b), absolute temperature (t) and solvent viscosity (η) to produce friction coefficient (ξ) and diffusion coefficient (d), applying the standard relationship for this problem in the order the calculation actually needs it.
What Is the Diffusion Coefficient Calculator?
The diffusion coefficient calculator turns boltzmann's constant, radius (a), major axis (a), minor axis (b), absolute temperature (t) and solvent viscosity (η) into friction coefficient (ξ) and diffusion coefficient (d).
It is a quick way to get from the numbers you have to the number you need, without setting up a spreadsheet or reaching for a formula.
How the Diffusion Coefficient Works
Each result follows from the ones before it, and the calculator shows every step, so a surprising answer can be traced back to the input that caused it.
Round your inputs to the precision you actually know, and keep more precision than that in the intermediate steps.
Getting a Result You Can Trust
Run the calculation twice with slightly different inputs. A sensible calculator moves its output in proportion; a wild change points to a unit or a decimal point problem in what you entered.
Write the inputs down next to the answer. It takes a moment and it is the difference between a number you can explain and one you cannot.
A Worked Example
Working through an example, with boltzmann's constant set to 10, radius (a) set to 5, major axis (a) set to 2, the calculator returns friction coefficient (ξ) of 471.2389, and friction coefficient (ξ) (fric coef 1) of 400, and friction coefficient (ξ) (fric coef 2) of 266.66667. Substitute your own figures and the same steps produce the same kind of answer.
Frequently Asked Questions
What do I need to work out friction coefficient (ξ)?
Enter boltzmann's constant, radius (a), major axis (a), minor axis (b), absolute temperature (t) and solvent viscosity (η). The calculator then works through the relationship and reports friction coefficient (ξ) and diffusion coefficient (d).
What does the diffusion coefficient actually calculate?
It takes boltzmann's constant, radius (a), major axis (a), minor axis (b), absolute temperature (t) and solvent viscosity (η) and converts them into friction coefficient (ξ) and diffusion coefficient (d) using the standard relationship for this problem. Each step is applied in turn, so every output is traceable back to the numbers you typed in.
How should I enter boltzmann's constant?
Use the value you actually have, in the unit shown next to the field. Enter every value in the same unit system. The calculator assumes the figures you supply are consistent, so it cannot correct a mistake that happens before the calculation starts.
Do I have to fill in every field?
Only the fields a particular result depends on. If you leave one blank, the results that need it simply show a note instead of a number, and everything else still works.
Is the answer exact?
It is as exact as the formula and the inputs allow. The method itself is the standard one for this problem, so the only sources of error are the figures you enter and the precision you ask for.