III.G.1.a.

Comparison of levels of theory for P-Si

Click on an entry for a histogram of the values.
The subscript refers to how many bonds of that type have been calculated.

average calculated bond lengths (Å)

Methods with predefined basis sets
semi-empirical	AM1	1.7416 4
	PM3	1.6288 4
	PM6	1.8902 4
composite	G2	2.0922 4
	G3	2.0922 4
	G3B3	2.1330 4
	CBS-Q	2.0922 4

average calculated bond lengths (Å)

Methods with standard basis sets
		STO-3G	3-21G	3-21G*	6-31G	6-31G*	6-31G**	6-31+G**	6-311G*	6-311G**	6-31G(2df,p)	TZVP	cc-pVDZ	cc-pVTZ	cc-pVQZ	aug-cc-pVDZ	aug-cc-pVTZ	aug-cc-pVQZ
hartree fock	HF	2.0432 4	2.1431 3	2.0797 4	2.2074 4	2.1281 3	2.0922 4	2.0938 4	2.0904 4	2.0904 4	2.0875 4	2.0968 4	2.1025 4	2.0909 4	2.0871 4	2.1085 4	2.0929 4	2.0878 4
hartree fock	ROHF	2.0065 3	2.1646 3	2.0416 3	2.1565 3	2.0534 3	2.0534 3	2.0553 3	2.0515 3	2.0515 3	2.0465 3		2.0615 3	2.0501 3	2.0461 3	2.0674 3	2.0524 3	2.0471 3
density functional	LSDA	2.0860 4	2.1816 4	2.1127 4	2.2146 4	2.1292 4	2.1292 4	2.1295 4	2.1224 4	2.1224 4	2.1169 4		2.1358 4	2.1182 4	2.0688 3	2.1375 4	2.1187 4	2.0688 3
	SVWN		2.2180 4			2.0851 3		2.1295 4
	BLYP	2.0812 4	2.2582 4	2.1438 4	2.2534 4	2.1634 4	2.1634 4	2.1640 4	2.1595 4	2.1595 4	2.1502 4		2.1685 4	2.1519 4
	B1B95	2.0700 4	2.0992 4	2.0992 4	2.2023 4	2.1127 4	2.1127 4	2.0742 3	2.1095 4	2.1095 4	2.1056 4		2.1215 4	2.1079 4	2.1034 4	2.1242 4	2.1089 4	2.1036 4
	B3LYP	2.0847 4	2.2285 4	2.1158 4	2.2241 4	2.1330 4	2.1330 4	2.1337 4	2.1287 4	2.1287 4	2.1222 4	2.1316 4	2.1395 4	2.1242 4	2.1193 4	2.1421 4	2.1253 4	2.1197 4
	B3LYPultrafine					2.1330 4
	B3PW91	2.0794 4	2.2198 4	2.1093 4	2.2128 4	2.1231 4	2.1231 4	2.1237 4	2.1190 4	2.1190 4	2.1142 4		2.1311 4	2.1167 4
	mPW1PW91	2.0735 4	2.2139 4	2.1036 4	2.2072 4	2.1170 4	2.1170 4	2.1176 4	2.1132 4	2.1132 4	2.1087 4		2.1252 4	2.1113 4
	M06-2X					2.1055 4
	PBEPBE	2.0702 4	2.2432 4	2.1326 4	2.2362 4	2.1480 4	2.1480 4	2.1485 4	2.1448 4	2.1448 4	2.1372 4		2.1545 4	2.1395 4	2.1352 4	2.2935 1	2.2758 1	2.1354 4
	HSEh1PBE					2.1196 4
Moller Plesset perturbation	MP2FC	2.0878 4	2.2499 4	2.1035 4	2.2418 4	2.1183 4	2.1183 4	2.1188 4	2.1128 4	2.1128 4	2.1186 4	2.1244 4	2.1400 4	2.1199 4		2.1468 4	2.1222 4
	MP2FU	2.0871 4	2.2504 4	2.1007 4	2.2418 4	2.1155 4	2.1155 4	2.1163 4	2.1121 4	2.1121 4	2.1073 4		2.1373 4	2.1122 4		2.2602 1	2.1105 4
	ROMP2	2.0574 3	2.2061 3	2.0680 3	2.2022 3	2.0823 3	2.0823 3	2.0829 3	2.0770 3	2.0770 3	2.0812 3		2.1021 3	2.0821 3	2.0732 3	2.1086 3	2.0844 3	2.0748 3
	MP3					2.1074 4
	MP4		2.2772 4			2.1331 4				2.1280 4				2.0951 3
	B2PLYP					2.1288 4		2.1296 4
Configuration interaction	CID		2.2331 4	2.0883 4	2.2255 4	2.1027 4			2.0973 4
Configuration interaction	CISD		2.2546 4	2.0941 4	2.2428 4	2.1090 4			2.1038 4
Quadratic configuration interaction	QCISD		2.3753 3	2.1075 4	2.2807 4	2.1245 4	2.1245 4	2.1253 4	2.1192 4	2.1192 4	2.1195 4		2.1464 4	2.1194 4
Quadratic configuration interaction	QCISD(T)					2.1335 4							2.1584 4	2.1315 4		2.1641 4	2.1335 4
Coupled Cluster	CCD		2.2417 4	2.0935 4	2.2342 4	2.1087 4	2.1087 4	2.1095 4	2.1029 4	2.1029 4	2.1081 4		2.1316 4	2.1086 4		2.1382 4	2.0760 3
	CCSD					2.1184 4
	CCSD(T)												2.1552 4	2.1290 4	2.0843 3	2.1611 4	2.1717 3	2.0853 3
	CCSD(T)=FULL					2.0905 3									2.0794 3			2.0789 3

average calculated bond lengths (Å)

Methods with effective core potentials (select basis sets)
		CEP-31G	CEP-31G*	CEP-121G	CEP-121G*	LANL2DZ	SDD
hartree fock	HF	2.2215 4	2.1118 4	2.2225 4	2.1076 4	2.2643 4	2.1422 3
density functional	B3LYP	2.2479 4	2.1535 4	2.2476 4	2.1508 4	2.2508 4	2.2319 4
Moller Plesset perturbation	MP2FC	2.2616 4	2.1489 4	2.2575 4	2.1428 4	2.2577 4	2.2473 4

For descriptions of the methods (AM1, HF, MP2, ...) and basis sets (3-21G, 3-21G*, 6-31G, ...) see the glossary in section I.C. Predefined means the basis set used is determined by the method.