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Z-matrix (chemistry)

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you convert Cartesian coordinates to a Z matrix and back again. While the transform is conceptually straightforward, algorithms of doing the conversion vary significantly in speed, numerical precision and parallelism. These matter because macromolecular chains, such as polymers, proteins, and DNA, can have thousands of connected atoms and atoms consecutively distant along the chain that may be close in Cartesian space (and thus small round-off errors can accumulate to large force-field errors.) The optimally fastest and most numerically accurate algorithm for conversion from torsion-space to cartesian-space is the Natural Extension Reference Frame method. Back-conversion from Cartesian to torsion angles is simple trigonometry and has no risk of cumulative errors.
1257: 107:, and more natural internal coordinates are used rather than Cartesian coordinates. The Z-matrix representation is often preferred, because this allows symmetry to be enforced upon the molecule (or parts thereof) by setting certain angles as constant. The Z-matrix simply is a representation for placing atomic positions in a relative way with the obvious convenience that the vectors it uses easily correspond to bonds. A conceptual pitfall is to assume all bonds appear as a line in the Z-matrix which is not true. For example: in ringed molecules like 79:, although it is not always the case that a Z-matrix will give information regarding bonding since the matrix itself is based on a series of vectors describing atomic orientations in space. However, it is convenient to write a Z-matrix in terms of bond lengths, angles, and dihedrals since this will preserve the actual bonding characteristics. The name arises because the Z-matrix assigns the second atom along the Z axis from the first atom, which is at the origin. 86:
and back, as the structural information content is identical, the position and orientation in space, however is not meaning the Cartesian coordinates recovered will be accurate in terms of relative positions of atoms, but will not necessarily be the same as an original set of Cartesian coordinates if
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programs. A skillful choice of internal coordinates can make the interpretation of results straightforward. Also, since Z-matrices can contain molecular connectivity information (but do not always contain this information), quantum chemical calculations such as geometry
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C 0.000000 0.000000 0.000000 H 0.628736 0.628736 0.628736 H -0.628736 -0.628736 0.628736 H -0.628736 0.628736 -0.628736 H 0.628736 -0.628736 -0.628736
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C 0.000000 0.000000 0.000000 H 0.000000 0.000000 1.089000 H 1.026719 0.000000 -0.363000 H -0.513360 -0.889165 -0.363000 H -0.513360 0.889165 -0.363000
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Parsons, Jerod; Holmes, J. Bradley; Rojas, J. Maurice; Tsai, Jerry; Strauss, Charlie E. M. (2005). "Practical conversion from torsion space to Cartesian space for in silico protein synthesis".
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Parsons, Jerod; Holmes, J. Bradley; Rojas, J. Maurice; Tsai, Jerry; Strauss, Charlie E. M. (2005). "Practical conversion from torsion space to Cartesian space forin silico protein synthesis".
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Reorienting the molecule leads to Cartesian coordinates that make the symmetry more obvious. This removes the bond length of 1.089 from the explicit parameters.
111:, a z-matrix will not include all six bonds in the ring, because all of the atoms are uniquely positioned after just 5 bonds making the 6th redundant. 915: 226:
Gordon, M. S.; Pople, J. A. (1968). "Approximate Self-Consistent Molecular-Orbital Theory. VI. INDO Calculated Equilibrium Geometries".
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C H 1 1.089000 H 1 1.089000 2 109.4710 H 1 1.089000 2 109.4710 3 120.0000 H 1 1.089000 2 109.4710 3 -120.0000
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The corresponding Z-matrix, which starts from the carbon atom, could look like this:
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may be performed faster, because an educated guess is available for an initial
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They are used for creating input geometries for molecular systems in many
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molecule can be described by the following Cartesian coordinates (in
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module to build a Z-matrix from Cartesian coordinates.
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Java implementation of the NERF conversion algorithm
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C++ implementation of the NERF conversion algorithm
1285: 312:Z-Matrix to Cartesian Coordinate Conversion Page 342: 225: 916:Fundamental (linear differential equation) 349: 335: 186: 147:Only the 1.089000 value is not fixed by 51:is a way to represent a system built of 1221:Matrix representation of conic sections 14: 1286: 168: 166: 164: 330: 29:Molecular modeling tool in chemistry 161: 24: 356: 317:Chemistry::InternalCoords::Builder 267:Journal of Computational Chemistry 175:Journal of Computational Chemistry 57:internal coordinate representation 25: 1310: 258: 55:. A Z-matrix is also known as an 1255: 1123:Used in science and engineering 228:The Journal of Chemical Physics 82:Z-matrices can be converted to 366:Explicitly constrained entries 219: 13: 1: 1140:Fundamental (computer vision) 154: 7: 906:Duplication and elimination 705:eigenvalues or eigenvectors 10: 1315: 839:With specific applications 468:Discrete Fourier Transform 114: 31: 1249: 1198: 1130:Cabibbo–Kobayashi–Maskawa 1122: 1068: 1004: 838: 757:Satisfying conditions on 756: 702: 641: 365: 36:meaning of this term see 1299:Computational chemistry 488:Generalized permutation 96:computational chemistry 1262:Mathematics portal 38:Z-matrix (mathematics) 84:Cartesian coordinates 149:tetrahedral symmetry 77:internal coordinates 18:Internal coordinates 1294:Molecular modelling 1211:Linear independence 458:Diagonally dominant 240:1968JChPh..49.4643G 92:molecular modelling 1216:Matrix exponential 1206:Jordan normal form 1040:Fisher information 911:Euclidean distance 825:Totally unimodular 1281: 1280: 1273:Category:Matrices 1145:Fuzzy associative 1035:Doubly stochastic 743:Positive-definite 423:Block tridiagonal 279:10.1002/jcc.20237 273:(10): 1063–1068. 248:10.1063/1.1669925 234:(10): 4643–4650. 197:10.1002/jcc.20237 181:(10): 1063–1068. 16:(Redirected from 1306: 1268:List of matrices 1260: 1259: 1236:Row echelon form 1180:State transition 1109:Seidel adjacency 991:Totally positive 851:Alternating sign 448:Complex Hadamard 351: 344: 337: 328: 327: 298: 252: 251: 223: 217: 216: 190: 170: 75:, the so-called 21: 1314: 1313: 1309: 1308: 1307: 1305: 1304: 1303: 1284: 1283: 1282: 1277: 1254: 1245: 1194: 1118: 1064: 1000: 834: 752: 698: 637: 438:Centrosymmetric 361: 355: 261: 256: 255: 224: 220: 171: 162: 157: 145: 139: 132: 117: 41: 30: 23: 22: 15: 12: 11: 5: 1312: 1302: 1301: 1296: 1279: 1278: 1276: 1275: 1270: 1265: 1250: 1247: 1246: 1244: 1243: 1238: 1233: 1228: 1226:Perfect matrix 1223: 1218: 1213: 1208: 1202: 1200: 1196: 1195: 1193: 1192: 1187: 1182: 1177: 1172: 1167: 1162: 1157: 1152: 1147: 1142: 1137: 1132: 1126: 1124: 1120: 1119: 1117: 1116: 1111: 1106: 1101: 1096: 1091: 1086: 1081: 1075: 1073: 1066: 1065: 1063: 1062: 1057: 1052: 1047: 1042: 1037: 1032: 1027: 1022: 1017: 1011: 1009: 1002: 1001: 999: 998: 996:Transformation 993: 988: 983: 978: 973: 968: 963: 958: 953: 948: 943: 938: 933: 928: 923: 918: 913: 908: 903: 898: 893: 888: 883: 878: 873: 868: 863: 858: 853: 848: 842: 840: 836: 835: 833: 832: 827: 822: 817: 812: 807: 802: 797: 792: 787: 782: 773: 767: 765: 754: 753: 751: 750: 745: 740: 735: 733:Diagonalizable 730: 725: 720: 715: 709: 707: 703:Conditions on 700: 699: 697: 696: 691: 686: 681: 676: 671: 666: 661: 656: 651: 645: 643: 639: 638: 636: 635: 630: 625: 620: 615: 610: 605: 600: 595: 590: 585: 583:Skew-symmetric 580: 578:Skew-Hermitian 575: 570: 565: 560: 555: 550: 545: 540: 535: 530: 525: 520: 515: 510: 505: 500: 495: 490: 485: 480: 475: 470: 465: 460: 455: 450: 445: 440: 435: 430: 425: 420: 415: 413:Block-diagonal 410: 405: 400: 395: 390: 388:Anti-symmetric 385: 383:Anti-Hermitian 380: 375: 369: 367: 363: 362: 354: 353: 346: 339: 331: 325: 324: 314: 309: 304: 299: 260: 259:External links 257: 254: 253: 218: 188:10.1.1.83.8235 159: 158: 156: 153: 143: 136: 129: 116: 113: 105:Hessian matrix 73:dihedral angle 28: 9: 6: 4: 3: 2: 1311: 1300: 1297: 1295: 1292: 1291: 1289: 1274: 1271: 1269: 1266: 1264: 1263: 1258: 1252: 1251: 1248: 1242: 1239: 1237: 1234: 1232: 1231:Pseudoinverse 1229: 1227: 1224: 1222: 1219: 1217: 1214: 1212: 1209: 1207: 1204: 1203: 1201: 1199:Related terms 1197: 1191: 1190:Z (chemistry) 1188: 1186: 1183: 1181: 1178: 1176: 1173: 1171: 1168: 1166: 1163: 1161: 1158: 1156: 1153: 1151: 1148: 1146: 1143: 1141: 1138: 1136: 1133: 1131: 1128: 1127: 1125: 1121: 1115: 1112: 1110: 1107: 1105: 1102: 1100: 1097: 1095: 1092: 1090: 1087: 1085: 1082: 1080: 1077: 1076: 1074: 1072: 1067: 1061: 1058: 1056: 1053: 1051: 1048: 1046: 1043: 1041: 1038: 1036: 1033: 1031: 1028: 1026: 1023: 1021: 1018: 1016: 1013: 1012: 1010: 1008: 1003: 997: 994: 992: 989: 987: 984: 982: 979: 977: 974: 972: 969: 967: 964: 962: 959: 957: 954: 952: 949: 947: 944: 942: 939: 937: 934: 932: 929: 927: 924: 922: 919: 917: 914: 912: 909: 907: 904: 902: 899: 897: 894: 892: 889: 887: 884: 882: 879: 877: 874: 872: 869: 867: 864: 862: 859: 857: 854: 852: 849: 847: 844: 843: 841: 837: 831: 828: 826: 823: 821: 818: 816: 813: 811: 808: 806: 803: 801: 798: 796: 793: 791: 788: 786: 783: 781: 777: 774: 772: 769: 768: 766: 764: 760: 755: 749: 746: 744: 741: 739: 736: 734: 731: 729: 726: 724: 721: 719: 716: 714: 711: 710: 708: 706: 701: 695: 692: 690: 687: 685: 682: 680: 677: 675: 672: 670: 667: 665: 662: 660: 657: 655: 652: 650: 647: 646: 644: 640: 634: 631: 629: 626: 624: 621: 619: 616: 614: 611: 609: 606: 604: 601: 599: 596: 594: 591: 589: 586: 584: 581: 579: 576: 574: 571: 569: 566: 564: 561: 559: 556: 554: 551: 549: 548:Pentadiagonal 546: 544: 541: 539: 536: 534: 531: 529: 526: 524: 521: 519: 516: 514: 511: 509: 506: 504: 501: 499: 496: 494: 491: 489: 486: 484: 481: 479: 476: 474: 471: 469: 466: 464: 461: 459: 456: 454: 451: 449: 446: 444: 441: 439: 436: 434: 431: 429: 426: 424: 421: 419: 416: 414: 411: 409: 406: 404: 401: 399: 396: 394: 391: 389: 386: 384: 381: 379: 378:Anti-diagonal 376: 374: 371: 370: 368: 364: 359: 352: 347: 345: 340: 338: 333: 332: 329: 322: 318: 315: 313: 310: 308: 305: 303: 300: 296: 292: 288: 284: 280: 276: 272: 268: 263: 262: 249: 245: 241: 237: 233: 229: 222: 214: 210: 206: 202: 198: 194: 189: 184: 180: 176: 169: 167: 165: 160: 152: 150: 142: 135: 128: 126: 122: 112: 110: 106: 102: 97: 93: 88: 85: 80: 78: 74: 70: 66: 62: 61:atomic number 58: 54: 50: 46: 39: 35: 27: 19: 1253: 1189: 1185:Substitution 1071:graph theory 568:Quaternionic 558:Persymmetric 270: 266: 231: 227: 221: 178: 174: 146: 140: 133: 118: 101:optimization 89: 81: 76: 56: 48: 42: 34:mathematical 26: 1160:Hamiltonian 1084:Biadjacency 1020:Correlation 936:Householder 886:Commutation 623:Vandermonde 618:Tridiagonal 553:Permutation 543:Nonnegative 528:Matrix unit 408:Bisymmetric 1288:Categories 1060:Transition 1055:Stochastic 1025:Covariance 1007:statistics 986:Symplectic 981:Similarity 810:Unimodular 805:Orthogonal 790:Involutory 785:Invertible 780:Projection 776:Idempotent 718:Convergent 613:Triangular 563:Polynomial 508:Hessenberg 478:Equivalent 473:Elementary 453:Copositive 443:Conference 403:Bidiagonal 155:References 69:bond angle 1241:Wronskian 1165:Irregular 1155:Gell-Mann 1104:Laplacian 1099:Incidence 1079:Adjacency 1050:Precision 1015:Centering 921:Generator 891:Confusion 876:Circulant 856:Augmented 815:Unipotent 795:Nilpotent 771:Congruent 748:Stieltjes 723:Defective 713:Companion 684:Redheffer 603:Symmetric 598:Sylvester 573:Signature 503:Hermitian 483:Frobenius 393:Arrowhead 373:Alternant 183:CiteSeerX 125:Ă…ngströms 45:chemistry 1069:Used in 1005:Used in 966:Rotation 941:Jacobian 901:Distance 881:Cofactor 866:Carleman 846:Adjugate 830:Weighing 763:inverses 759:products 728:Definite 659:Identity 649:Exchange 642:Constant 608:Toeplitz 493:Hadamard 463:Diagonal 287:15898109 205:15898109 67:length, 49:Z-matrix 32:For the 1170:Overlap 1135:Density 1094:Edmonds 971:Seifert 931:Hessian 896:Coxeter 820:Unitary 738:Hurwitz 669:Of ones 654:Hilbert 588:Skyline 533:Metzler 523:Logical 518:Integer 428:Boolean 360:classes 295:2279574 236:Bibcode 213:2279574 121:methane 115:Example 109:benzene 1089:Degree 1030:Design 961:Random 951:Payoff 946:Moment 871:Cartan 861:BĂ©zout 800:Normal 674:Pascal 664:Lehmer 593:Sparse 513:Hollow 498:Hankel 433:Cauchy 358:Matrix 293:  285:  211:  203:  185:  71:, and 47:, the 1150:Gamma 1114:Tutte 976:Shear 689:Shift 679:Pauli 628:Walsh 538:Moore 418:Block 291:S2CID 209:S2CID 53:atoms 956:Pick 926:Gram 694:Zero 398:Band 321:Perl 283:PMID 201:PMID 119:The 94:and 65:bond 1045:Hat 778:or 761:or 275:doi 244:doi 193:doi 127:): 43:In 1290:: 319:— 289:. 281:. 271:26 269:. 242:. 232:49 230:. 207:. 199:. 191:. 179:26 177:. 163:^ 151:. 63:, 1175:S 633:Z 350:e 343:t 336:v 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Index

Internal coordinates
mathematical
Z-matrix (mathematics)
chemistry
atoms
atomic number
bond
bond angle
dihedral angle
Cartesian coordinates
molecular modelling
computational chemistry
optimization
Hessian matrix
benzene
methane
Ångströms
tetrahedral symmetry



CiteSeerX
10.1.1.83.8235
doi
10.1002/jcc.20237
PMID
15898109
S2CID
2279574
Bibcode

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