Your NMR simulator will solve the Bloch equation numerically. Look on Wikipedia

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Your NMR simulator will solve the Bloch equation numerically. Look on Wikipedia or other online resources to learn more about this equation (or set of equations)-but ignore any terms involving relaxation times such as T1 or 12. We have: dM vector/dt = gamma M vector times B vector Notice that the SI units of gamma must be Hz/T, and that as long as we are interested only in the direction of M, that is, we are treating it as a unit vector, its units don't matter. Look up gamma for a proton, that is, for the nucleus of an H atom. Also look up B for the earth's field. Now you're ready to give it a try: Start with a spin (M vector) pointing along x at t=0, and assume B vector has a magnitude of the earth's field, pointing along z. Numerically calculate the evolution of M vector with time, for an appropriate amount of time such that the precession of M vector can be clearly seen. Examine your output in spherical coordinates for a clearer idea of what you are getting. One subtlety is how small to make the timesteps of your numerical simulator: if they are too small, it will take forever to do the calculation over an appropriate amount of time. If they are too long, you will not have an accurate numerical simulation. Play with this quantity to get it right. Now try a piecewise function for B(t): Set B vector along z for an amount of time corresponding to 3.5 periods, then switch the direction of B to point along y for another 3.5 periods. Where do you end up? (And watch the evolution...) Morning of Sept 18: Hand in your code and your results for step 2, expressed as x(t), y(t), z(t), theta(t), and phi(t)-that is, there should be 5 graphs plus some code. I

Explanation / Answer

I think that fulfils your requirement for being able to do the prediction using open-source programs.

As for scripting, there is a mention in the paper of wrapping the whole thing up in a python script (and to my knowledge, there isn't actually a GUI for either piece of the aforementioned programs), so it should be amenable to this.

One thing that it doesn't appear to do, is to graphically plot the resulting data generated (I believe they just compare a list of values to a list of experimental values), but you should be able to plot this in something like MatLab, or, if you play enough, it should be importable into TopSpin via something to turn it into a set of suitably written values.

Concerning the algorithms, there are references on the nmrdb.org website. For 1H prediction we are using Spinus (based on the neural network). For 13C we are using NMR shift DB that is based on hose code.

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