This folder contains two files for the data as plotted in Fig. 4(b). In file Figure_4.csv, the data for 1/T1 as a function of the temperature is contained. File Figure_4_Fit contains the fit function as presented in the main text and the parameter A_1 as determined in our analysis. Please note that the fit function and its parameters are taken from [1]. 

[1] A. Jarmola, V. M. Acosta, K. Jensen, S. Chemerisov, and D.  Budker,  Temperature-  and  magnetic-field-dependent longitudinal spin relaxation in nitrogen-vacancy ensembles  in  diamond,  Physical  Review  Letters 108, 197601 (2012).