. Author manuscript; available in PMC: 2020 Sep 9.

Published in final edited form as: J Mol Model. 2019 Sep 9;25(10):307. doi: 10.1007/s00894-019-4194-1

Table 1.

Accuracy and performance of Ewald, sPME and FFP for single Coulomb energy/force calculations of a 512 GEM* water box using a B–spline order of 8. All calculations were performed on an i7–5820K@3.3GHz using a single core.

grid size = 200³
C–D exp	PME		FFP		Ewald
	E^Coul	t (s)	E^Coul	t (s)	E^Coul	t (s)
0.100	−7761.784660	6.72	−7761.784660	156.62	–	–
0.250	−7761.784659	6.04	−7761.784659	52.52	–	–
0.500	−7761.784724	6.42	−7761.784718	21.99	–	–
1.250	−7761.775239	6.51	−7538.336333	12.26	–	–
2.000	−7761.760290	6.46	6817.189360	10.17	–	–
grid size = 150³
	PME		FFP		Ewald
	E^Coul	t (s)	E^Coul	t (s)	E^Coul	t (s)
0.100	−7761.784660	4.56	−7761.784660	62.55	–	–
0.250	−7761.784661	4.37	−7761.784659	21.74	–	–
0.500	−7761.784238	4.24	−7761.784720	10.17	–	–
1.250	−7761.658504	4.26	−7619.653416	5.71	–	–
2.000	−7761.692765	4.83	2518.484768	4.85	–	–
grid size = 100³
	PME		FFP		Ewald
	E^Coul	t (s)	E^Coul	t (s)	E^Coul	t (s)
0.100	−7761.784659	2.50	−7761.784660	19.42	−7761.784660	410.56
0.250	−7761.784643	2.13	−7761.784659	7.59	−7761.784659	408.89
0.500	−7761.791994	1.96	−7761.784723	3.82	−7761.784677	406.25
1.250	−7757.544636	1.93	−7709.917195	2.47	−7758.809650	410.10
2.000	−7787.095605	1.92	−2837.159878	2.53	−7787.734594	387.86
grid size = 50³
	PME		FFP		Ewald
	E^Coul	t (s)	E^Coul	t (s)	E^Coul	t (s)
0.100	−7761.784675	1.95	−7761.784660	4.22	−7761.784660	64.51
0.250	−7761.788669	1.46	−7761.784888	2.21	−7761.784659	64.05
0.500	−7734.891895	1.18	−7753.682565	1.42	−7747.938468	65.00
1.250	57367.505736	1.26	−41549.335491	1.22	45434.658996	64.72
2.000	−7761.692765	1.16	−13677.969316	1.17	9852.239609	61.69