Estimated values for alpha N2 from the polynomial in:
Fray, N., and B. Schmitt 2009.  Sublimation of ices of astrophysical interest: A bibliographic review.  Planet. Space Sci. 57, 2053-2080.
T(K)     P(bar)
20.00   8.53e-15
21.00   7.60e-14
22.00   5.56e-13
23.00   3.42e-12
24.00   1.81e-11
25.00   8.42e-11
26.00   3.47e-10
27.00   1.29e-09
28.00   4.36e-09
29.00   1.35e-08
30.00   3.90e-08
31.00   1.05e-07
32.00   2.64e-07
33.00   6.31e-07
34.00   1.43e-06
35.00   3.09e-06
