Table S1.

Parameters for bi-exponential curves A exp(t/τ₁) + B exp(t/τ₂) + C fitted to the average radius of gyration over time for each forcefield model and starting conformation.

model	conf	A (Å)		B(Å)		C(Å)		τ1(ns)		τ2 (ns)
ff94	0	5.033	± 0.345	0.794	± 0.004	7.795	± 0.001	2.493	± 0.360	57.757	±0.354
	l	5.006	0.704	0.517	0.004	7.820	0.001	1.967	0.473	48.438	0.259
	2	4.950	0.374	0.461	0.003	8.147	0.002	2.507	0.389	84.182	0.751
	3	5.018	0.397	0.846	0.005	8.133	0.001	2.506	0.426	45.982	0.345
	4	4.981	0.744	1.107	0.007	8.240	0.001	2.187	0.623	40.717	0.362
	5	5.070	41.314	0.561	0.003	7.656	0.004	0.867	5.824	134.93	1.281
	6	5.014	-	1.404	0.004	7.948	0.001	0.157	-	61.837	0.449
	7	4.952	-	0.460	0.002	7.678	0.001	0.370	-	81.967	0.448
	8	5.032	0.693	0.663	0.004	7.864	0.001	1.953	0.460	49.997	0.282
	9	5.020	1.677	0.444	0.004	8.241	0.001	1.533	0.717	42.272	0.256
ff96	0	5.043	0.662	0.992	0.009	9.350	0.002	2.454	0.688	43.309	0.563
	1	4.955	0.587	0.566	0.008	8.929	0.002	2.456	0.606	43.875	0.476
	2	4.979	4.446	0.500	0.006	9.163	0.002	1.442	1.670	50.432	0.543
	3	4.837	0.832	0.239	0.004	9.379	0.005	2.177	0.668	99.665	1.574
	4	4.807	0.364	1.074	0.007	9.697	0.004	3.115	0.583	74.105	1.387
	5	−1.262	1.172	1.304	1.176	9.037	0.004	26.411	7.628	41.577	11.188
	6	−1.433	0.108	1.515	0.019	8.750	0.001	4.805	0.474	36.572	0.632
	7	−1.541	0.962	1.045	0.964	8.997	0.005	31.123	7.958	51.380	13.122
	8	0.550	0.016	0.400	0.010	8.444	0.012	18.133	0.522	124.259	5.210
	9	0.522	0.028	0.404	0.030	8.628	0.001	7.164	0.402	30.423	0.610
ff99	0	1.113	0.027	0.779	0.006	7.840	0.002	7.309	0.227	66.321	0.655
	1	0.963	0.014	0.332	0.004	7.921	0.008	10.618	0.227	138.224	2.921
	2	0.771	0.016	0.561	0.005	8.095	0.007	11.026	0.286	114.416	2.380
	3	1.067	0.026	0.672	0.007	8.477	0.003	7.963	0.268	79.218	1.161
	4	1.440	0.014	0.604	0.006	8.258	0.013	14.344	0.403	141.921	5.159
	5	1.009	-	0.612	0.002	7.829	0.002	0.055	-	81.050	0.513
	6	1.096	-	1.305	0.004	8.079	0.001	0.149	-	45.977	0.327
	7	−1.639	0.077	0.604	0.003	7.716	0.005	3.980	0.195	125.616	1.470
	8	1.128	0.022	0.494	0.014	7.866	0.001	7.816	0.279	41.492	0.485
	9	0.533	0.021	0.089	0.010	8.270	0.017	23.216	0.601	143.168	7.718
ff99ϕ	0	1.020	0.028	0.630	0.021	8.386	0.035	8.861	0.622	77.890	14.298
	1	1.160	0.029	0.437	0.017	7.850	0.030	12.616	0.599	174.122	11.908
	2	0.708	0.138	0.639	0.154	8.289	0.006	17.907	2.385	53.769	4.931
	3	1.388	0.240	0.942	0.013	8.387	0.008	4.552	0.780	80.028	2.651
	4	1.479	0.199	1.406	0.114	8.655	0.003	5.569	1.561	23.287	1.543
	5	0.358	-	0.872	0.006	7.841	0.008	0.095	-	116.315	2.487
	6	0.587	0.049	1.159	0.056	7.737	0.073	11.707	0.863	232.291	31.895
	7	0.497	-	0.437	0.012	7.852	0.015	0.128	-	155.409	4.771
	8	1.197	0.031	0.332	0.009	7.963	0.016	12.026	0.645	123.404	5.806
	9	0.545	-	0.624	0.008	8.160	0.003	0.482	-	47.257	0.713
ff03	0	1.285	0.027	0.630	0.011	8.386	0.006	8.861	0.381	77.890	2.070
	1	0.931	0.024	0.533	0.009	7.943	0.014	8.203	0.255	140.234	4.637
	2	0.583	0.015	0.218	0.008	8.442	0.018	13.182	0.433	128.283	6.417
	3	0.382	0.016	0.825	0.057	8.213	0.068	12.315	0.392	251.316	29.238
	4	1.795	0.049	0.839	0.018	8.550	0.004	6.876	0.450	52.116	1.267
	5	0.657	0.356	0.361	0.005	8.190	0.003	2.423	0.369	58.054	0.680
	6	0.834	0.044	0.664	0.019	8.273	0.042	22.166	1.213	143.512	17.958
	7	−0.681	0.026	0.352	0.033	8.085	0.002	9.314	0.451	38.338	1.003
	8	0.525	0.019	0.833	0.020	8.202	0.005	11.543	0.452	67.408	1.962
	9	0.448	0.275	0.571	0.008	8.487	0.002	2.592	0.343	35.544	0.396

Blank error estimates represent cases where the fitted τ₁ was very close to zero, which our error model treats poorly (see Methods).