Three complexity criteria were defined (here...), all techniques confused : total number of independent atoms C1 and number of refined x,y,z parameters Nc for complexity level in the refinememt, C2 for complexity level in structure determination (number of independent atoms obtained from application of direct or Patterson methods : the starting model allowing then completion of the structure determination by Fourier syntheses). More about C1 and C2 is available. Those with letters in the C2 column are structures determined by model building approaches, possibly by locating molecule(s) or fragment(s) in the cell by simulated annealing, Monte Carlo, Genetic Algorithm (...). They are also classified according to C3, C4 and C5 complexity criteria.
A classification of the more complex structures according to Nc gives approximately the same result than according to C1 :
Formula space group C1 Nc C2 radiation T3R3 Zn-human insulin R3 1630 4893 MB Sync Sapo-40 P2/n 62 182 9 XC12+Sync La3Ti5Al15O37 Cc 60 178 5 Sync+N thiothixene P21 59 177 GOM Sync (Rb44K4[Si96Zn24O240]. 48H(2)O), VPI-9, P42/ncm 59 170 Sync (UO2)3H2(HO3PC6H5)4.H2O P212121 50 150 11 XC12 Capsaicin P21/c 49 147 GOM Sync C24H16O7 P-1 47 141 14 Sync C60Br24(Br2)2 P-1 44 42 MB Sync (CH3(CH2)16COO)2CaH2O P21/c 42 126 MB Sync Promazine Hydrochloride P21/c 41 123 GOM Sync [(CH3)2NH2]4Mo6O20.2H2O P21 38 113 6 XC12 poly(ethylene oxide)3 LiN(SO2CF3)2 P21/c 37 111 MC XC1 MCS-I Pca21 36 15 Y17.33(BO3)4(B2O5)2O16 Cm 32 62 9 XC12 Zr2(NaPO4)4.6H2O P1 32 93 10 XC12 C11H14N6 P-1 31 93 MB XC1 S6C24 (T6) P21/a 30 90 G XC12 Bi(H2O)4(OSO2CF3)3 P21/c 29 87 14 XC1 Ga2(HPO3)3.4H2O P21 29 86 2 Sync+N Beta-Ba3AlF9 Pnc2 29 74 7 XC12 [Si32B4O72][N(CH3)4]4 P21/a 28 84 MB Sync+XC1 C10H16O Cmcm 27 81 11 Sync 2(C6H5NH3).Mo3O10.4H2O Pnma 27 70 18 XC12 (AlPO4)3.(CH3)4NOH P21212 26 70 6 XC12 S5C20 (T5) P21/a 25 75 G XC12 Fluorescein Pn21a 25 75 MC Sync a-Zr(OH)2(NO3)2.1.65H2O P-1 25 75 2 XC1 (NH4)2(Ti3O2)(HPO4)2(PO4)2 P21 25 74 10 XC12 K7Na7Be14P14O56.20H2O P321 25 63 MB Sync beta-Zr(OH)2NO3(2).H2O P-1 24 72 2 XC1 Li-3[Co(CN)5].2DMF P21/n 24 72 MC Sync C16H22N6 P3 24 70 MB XC1 Mg6Co2D11 Pnma 24 63 Sync+N Chlorothiazide-I P1 23 48 17 Sync Pb(O3PC6H5) P-1 22 66 2 XC12 Nb3(NbO)2(PO4)7 C2/c 22 62 7 Sync Zn[HO3P(C6H4)2PO3H] P-1 21 63 3 XC12 La4Ti9O24 Fddd 21 53 2 Sync Zr2(PO4)(O3PCH2CH2(viologen)CH2CH2PO3)X(3).3H(2)O, X = halide P2/c 20 60 2 XC12+Sync [HgRu(CO)4]4 P21/n 20 60 MM XC12 S4C16 (T4) P21/a 20 60 G XC12 [(CH3)4NOH]4Si34.4Al1.6O72 C2/m 20 50 en SYNC C6H10N2O2 P21/n 20 30 MB XC1 Ti2O(PO4)2(H2O)2 P-1 19 57 15 XC12+Sync+N C13H17N2O4 P21/a 19 57 MB XC1 Fe2V4O13 P21/c 19 57 6 XC12 C10H19N2O20P3Zr2 P21/c 19 55 3 XC12+Sync beta-VO(HPO4).2H2O P-1 18 54 12 XC12 calcined AlPO4-18 C2/c 18 54 XC1 C9H5O4NSCu.2H2O P-1 18 54 2 XC1 C16H22Cl4N4Ni2O2 P-1 18 54 2 XC12 MeALPO-36 C-1 18 54 DLS XC12 PEO3:LiCF3SO3 P21/a 18 54 A XC1 alpha-NaCaAlF6 P21/c 18 54 17 XC12 Al2(HPO3)3.4H2O P21 18 53 7 Sync BaC2O4 3.5H2O C2/c 18 52 4 Sync p-BrC6H4CH2CO2H P21/n 17 51 1 XC1 Zr2(O3PCH2CH2-viologen-CH2CH2PO3)F6.2H2O P21/c 17 51 2 XC12 [Si64O128].4C10H17N I41/amd 17 33 9 Sync Zr(OH)2(NO3)2.4.7H2O P-1 16 48 1 XC1 PeO4 : NH4SCN C2/c 16 48 1 XC1 K2TiSi3O9.H2O P212121 16 48 16 XC12 (NH4)4(MoO2)4O3(C4H3O5)2 C2 16 43 2 XC1 Fe4V2Mo3O20 P4122 16 42 6 XC12 KCuTa3O9 Pnc2 16 38 3 XC12 Li29Zr9Nb3O40 Immm 16 20 3 XC1 Ti2O(PO4)2(H2O)2 P-1 15 45 15 XC12 Ca3Hf2Si2O9 P21/c 15 45 1 XC12+N Li6P6O18 P21/n 15 45 12 XC12 NiV2O6 P-1 15 42 9 XC12 Cr8O21 P-1 15 42 12 XC1+Sync+N [Pd(NH3)4]Cr2O7 P21/c 15 39 4 XC12 Cu2(OH)3(CH3COO).H2O P21/m 15 35 3 XC12 [(CH3)4N]4Ge4S10 P-43n 15 33 8 XC1 Sr3La2Ti2O10 P21/m 15 16 G XC12 1-methylfluorene P21/n 14 52 MC XC1 alpha-VO(HPO4).2H2O P21/c 14 42 5 XC12+N Cu2WO4 P-1 14 42 6 XC1+N LaMo5O8 P21/a 14 42 6 Sync+N U(UO2)(PO4)2 P-1 14 42 2 XC1+N beta-BaAlF5 P21/n 14 42 2 XC12+N C11H14O3 (ortho-thymotic acid) P21/n 14 42 GA XC1 gamma-BaAlF5 P21 14 41 2 XC12+N MoO2(O3PC6H5).H2O P222 14 41 2 XC12 [Cu(C7H5N2O4)2]n P21/c 14 39 1 XC12 SiO2 (ITQ-4) I2/m 14 37 14 Sync Ti3(PO4)4(H2O)2.NH3 P-1 14 36 14 XC12 gamma-Zn2P2O7 Pbcm 14 35 14 XC1 RbC5H5-I Pbcm 14 34 8 Sync gamma-CsAlF4 Pnma 14 30 3 XC12 UO2(O3PC6H5).0.7H2O P6/mcc 14 27 1 XC12 Zr(NaPO4)(HPO4).H2O P21/c 13 39 2 XC12 Zr(PO4)(H2PO4).2H2O P21 13 38 MB XC12 Na2Ca(HPO4)2 P21 13 38 10 XC12 (VO)3(PO4)2.9H2O P21/n 13 36 8 Sync ZrKH(PO4)2 P2/c 13 35 1 XC12 ZrNaH(PO4)2 P2/c 13 35 2 XC12 Bi7F11O5 C2 13 32 4 XC12 CaZrTi2O7 C2/c 13 32 MB XC12 [N(CH3)4]Mo4O12 C2/c 13 25 5 XC12 Sr2Mg3H10 C2/m 13 24 5 XC1+N Tl5Ba3Sr5Cu3O19 A2mm 13 13 ? XC12back