THE JOINT PROBABILITY-DISTRIBUTION OF ANY SET OF PHASES GIVEN ANY SET OF DIFFRACTION MAGNITUDES .3. A FUNCTION TO MAXIMIZE

被引：4

作者：

CASCARANO, G ^{[1
]}

GIACOVAZZO, C ^{[1
]}

MOLITERNI, AGG ^{[1
]}

POLIDORI, G ^{[1
]}

机构：

[1] UNIV PERUGIA,DIPARTIMENTO SCI TERRA,I-06100 PERUGIA,ITALY

来源：

ACTA CRYSTALLOGRAPHICA SECTION A | 1994年 / 50卷

关键词：

D O I：

10.1107/S0108767393004702

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

The joint probability distribution method described in paper I [Giacovazzo, Burla & Cascarano (1992). Acta Cryst. A48, 901-906] and paper II [Burla, Cascarano & Giacovazzo (1992). Acta Cryst. A48, 906-912] of this series has been considered in order to obtain a function that is maximized by the true crystal structure. The phasing process is carried out by maximizing such a function via a modified tangent refinement: this implies the active use of negative triplet and quartet relationships. The major effects provoked in a direct procedure by the use of numerous phase relationships with expected negative cosines are analysed. Practical applications are also described.

引用

页码：22 / 27

页数：6

共 24 条

[1] COMPLETION AND REFINEMENT OF CRYSTAL-STRUCTURES WITH SIR92 [J].

ALTOMARE, A ;

CASCARANO, G ;

GIACOVAZZO, C ;

GUAGLIARDI, A .

JOURNAL OF APPLIED CRYSTALLOGRAPHY, 1993, 26 (pt 3) :343-350

[2] ON THE RELIABILITY OF QUARTET ESTIMATES [J].

ALTOMARE, A ;

BURLA, MC ;

CASCARANO, G ;

GIACOVAZZO, C ;

GUAGLIARDI, A .

ACTA CRYSTALLOGRAPHICA SECTION A, 1993, 49 :342-346

[3] STEREOSELECTIVE ALDOL CONDENSATION OF 3,4-DIHYDRO-3-OXO-2H-1,4-BENZOTHIAZINES - X-RAY DETERMINATION OF THE ALDOL STEREOSTRUCTURE [J].

BABUDRI, F ;

FLORIO, S ;

ZUCCARO, L .

TETRAHEDRON, 1985, 41 (03) :569-573

[4]

BROMLEY L, 1990, COMMUNICATION

[5] THE JOINT PROBABILITY-DISTRIBUTION OF ANY SET OF PHASES GIVEN ANY SET OF DIFFRACTION MAGNITUDES .2. PRACTICAL APPLICATIONS [J].

BURLA, MC ;

CASCARANO, G ;

GIACOVAZZO, C .

ACTA CRYSTALLOGRAPHICA A-FOUNDATION AND ADVANCES, 1992, 48 :906-912

[6] A WEIGHTING SCHEME FOR TANGENT FORMULA DEVELOPMENT .3. THE WEIGHTING SCHEME OF THE SIR PROGRAM [J].

BURLA, MC ;

CASCARANO, G ;

GIACOVAZZO, C ;

NUNZI, A ;

POLIDORI, G .

ACTA CRYSTALLOGRAPHICA SECTION A, 1987, 43 :370-374

[7] SIR88 - A DIRECT-METHODS PROGRAM FOR THE AUTOMATIC SOLUTION OF CRYSTAL-STRUCTURES [J].

BURLA, MC ;

CAMALLI, M ;

CASCARANO, G ;

GIACOVAZZO, C ;

POLIDORI, G ;

SPAGNA, R ;

VITERBO, D .

JOURNAL OF APPLIED CRYSTALLOGRAPHY, 1989, 22 :389-393

[8] IMPROVED FIGURES OF MERIT FOR DIRECT METHODS [J].

CASCARANO, G ;

GIACOVAZZO, C ;

GUAGLIARDI, A .

ACTA CRYSTALLOGRAPHICA SECTION A, 1992, 48 :859-865

[9] FIGURES OF MERIT IN DIRECT METHODS - A NEW POINT-OF-VIEW [J].

CASCARANO, G ;

GIACOVAZZO, C ;

VITERBO, D .

ACTA CRYSTALLOGRAPHICA SECTION A, 1987, 43 :22-29

[10] THE METHOD OF REPRESENTATIONS OF STRUCTURE SEMINVARIANTS - THE STRENGTHENING OF TRIPLET RELATIONSHIPS [J].

CASCARANO, G ;

GIACOVAZZO, C ;

CAMALLI, M ;

SPAGNA, R ;

BURLA, MC ;

NUNZI, A ;

POLIDORI, G .

ACTA CRYSTALLOGRAPHICA SECTION A, 1984, 40 (MAY) :278-283

← 1 2 3 →