Table 15. Hydrogen Bonding Distances in Å for Small Phosphorus Containing Systems: Deviations in Comparison to B3LYP/aug-cc-pVTZ.

system	H-bond	B3LYPa	MP2a	B3LYPb	B3LYPc	PBEc	PDDGd	MIO	3OB
DMPH–OH2	HOH–O	1.892	–0.028	–0.004	+0.025	–0.029	–0.219	–0.062	–0.010
DMPH–OH2	H–OH2	1.776	–0.031	–0.055	–0.009	–0.081	–0.090	+0.018	+0.075
DMP–1–H2O	HOH–O1	2.052	–0.036	–0.028	–0.004	–0.031	–0.322	–0.170	–0.125
DMP–1–H2O	HOH–O2	2.093	–0.060	–0.031	+0.009	–0.023	–0.360	–0.191	–0.144
MMPH–OH2	H–OH2	1.773	–0.031	–0.054	–0.015	–0.087	–0.084	+0.020	+0.072
MMPH–OH2	O–HOH	1.916	–0.034	–0.015	+0.024	–0.037	–0.239	–0.091	–0.034
MMP–1–H2O	HOH–O1	2.064	–0.046	–0.040	–0.002	–0.034	–0.329	–0.183	–0.140
MMP–1–H2O	HOH–O2	2.073	–0.043	–0.031	+0.008	–0.024	–0.335	–0.178	–0.127
MMP–1–OH2	H–OH2	2.113	–0.063	–0.136	–0.019	–0.125	–0.346	–0.205	–0.102
MMP–1–OH2	O–HOH	1.638	–0.009	+0.093	+0.008	–0.030	0.003	+0.029	+0.001
MMP–2–H2O	HOH–O1	1.862	–0.040	–0.007	+0.009	–0.026	–0.193	–0.113	–0.115
MMP–2–H2O	HOH–O2	1.861	–0.040	–0.007	+0.009	–0.026	–0.192	–0.112	–0.114
MAD			0.038	0.042	0.012	0.046	0.226	0.114	0.088
MAX			0.063	0.136	0.025	0.125	0.360	0.205	0.142

^aBasis set is aug-cc-pVTZ.

^bBasis set is 6-31G(d); this method is used within G3B3 for the geometry optimization.

^cBasis set is 6-31+G(d,p).

^dOptimization using PM6 often leads to very different geometries; thus only PDDG results are reported. See Supporting Information.