Foods Rich in Magnesium to relax the nervous system:
Food / Mg per 100 grammes
Pumpkin seeds 535
Dark chocolate 500
White and Black beans 110-135
Other good sources include spinach and all leafy greens, artichokes and kelp, brewers yeast, treacle, buckwheat, hazelnuts, pecans, Brazil nuts, walnuts, millet, rye and tofu, wheatgerm.
I would just give a word of caution about eating too much millet and buckwheat, as these are quite drying grains, which if you eat them regularly will aggravate your Vata dosha, but a little will be fine.