modify your search
Results for DC.creator="H." AND DC.creator="A." AND DC.creator="Hauptman" page 1 of 2 pages. |
Ab initio phasing
International Tables for Crystallography (2012). Vol. F, ch. 16.1, pp. 413-432 [ doi:10.1107/97809553602060000850 ]
... small-molecule structures have been routinely solved by direct methods, a class of ab initio methods in which probabilistic phase relations ... macromolecular structures in this way has, however, been limited to a few special cases involving relatively small macromolecules, unusually high-resolution ... approaches, including one that does not require high-resolution data, a related molecule as search fragment or heavier atoms and ...
CRUNCH2 - Karle-Hauptman determinants
International Tables for Crystallography (2012). Vol. F, Section 16.1.12.7, p. 429 [ doi:10.1107/97809553602060000850 ]
CRUNCH2 - Karle-Hauptman determinants 16.1.12.7. CRUNCH2 - Karle-Hauptman determinants The program CRUNCH2 is quite different to the other ... of some E-map recycling at the end to complete a substructure, CRUNCH2 operates entirely in reciprocal space by maximizing ...
[more results from section 16.1.12 in volume F]
Substructure solution for native sulfurs and halide soaks
International Tables for Crystallography (2012). Vol. F, Section 16.1.11, pp. 425-426 [ doi:10.1107/97809553602060000850 ]
... the incorporation of heavy-metal ions by soaking crystals with a low concentration of the metal salt for several hours. The ... not work well for all expression systems; the second had a low success rate. The improved quality of modern diffraction data ... sulfur atoms or from halide ions introduced by soaking with a high concentration of a halide (iodide or bromide) for ...
Substructure applications
International Tables for Crystallography (2012). Vol. F, Section 16.1.10.4, p. 425 [ doi:10.1107/97809553602060000850 ]
... known for some time that conventional direct methods can be a valuable tool for locating the positions of heavy-atom substructures ... when applied to such data. Dual-space direct methods provide a more robust foundation for handling such data, which are often ... care in data processing, especially if the values resulting from a MAD experiment are to be used. SHELXD is frequently ...
[more results from section 16.1.10 in volume F]
Recognizing solutions
International Tables for Crystallography (2012). Vol. F, Section 16.1.9.3, pp. 421-422 [ doi:10.1107/97809553602060000850 ]
... progress of current SnB jobs can be followed by monitoring a figure-of-merit histogram for the trial structures that have been processed (Fig. 16.1.9.2). A clear bimodal distribution of figure-of-merit values is a strong indication that a solution has, in fact, been ...
[more results from section 16.1.9 in volume F]
Utilizing Pattersons for better starts
International Tables for Crystallography (2012). Vol. F, Section 16.1.8, pp. 419-420 [ doi:10.1107/97809553602060000850 ]
... are present, it is possible to start recycling procedures from a set of atomic positions that are consistent with the Patterson ... This filter is currently implemented as follows in SHELXD. First, a sharpened Patterson function (Sheldrick et al., 1993) is calculated, and ... the top 200 (for example) non-Harker peaks further than a given minimum distance from the origin are selected, in ...
Resolution enhancement: the `free lunch' algorithm
International Tables for Crystallography (2012). Vol. F, Section 16.1.7, p. 419 [ doi:10.1107/97809553602060000850 ]
... 16.1.7. Resolution enhancement: the `free lunch' algorithm Direct methods take a set of phases, refine them and also determine new ones. ... to predict new amplitudes as well. If density modification of a real-space map is performed, then any process of real-space density modification will, following a Fourier transformation, give structure-factor amplitudes for reflections that ...
Fourier refinement
International Tables for Crystallography (2012). Vol. F, Section 16.1.6, p. 419 [ doi:10.1107/97809553602060000850 ]
... that can only be generated using the larger E magnitudes, a limited number of reflections are phased during the actual dual-space cycles. Working with a limited amount of data has the added advantage that less ... current trial structure is the `best' so far based on a figure of merit (either the minimal function or a ...
Random omit maps
International Tables for Crystallography (2012). Vol. F, Section 16.1.5.3, p. 419 [ doi:10.1107/97809553602060000850 ]
Random omit maps 16.1.5.3. Random omit maps A third peak-picking strategy involves selecting approximately of the top ... the common practice in macromolecular crystallography of omitting part of a structure from a Fourier calculation in the hope of finding an improved ...
[more results from section 16.1.5 in volume F]
Parameter shift
International Tables for Crystallography (2012). Vol. F, Section 16.1.4.3, p. 418 [ doi:10.1107/97809553602060000850 ]
... be used to minimize by varying the phases. So far, a seemingly simple algorithm, known as parameter shift (Bhuiya & Stanley, 1963 ... to reduce the value of the minimal function. For example, a typical phase-refinement stage consists of three iterations or scans through the reflection list, with each phase being shifted a maximum of two times by 90° in either the ...
[more results from section 16.1.4 in volume F]
International Tables for Crystallography (2012). Vol. F, ch. 16.1, pp. 413-432 [ doi:10.1107/97809553602060000850 ]
... small-molecule structures have been routinely solved by direct methods, a class of ab initio methods in which probabilistic phase relations ... macromolecular structures in this way has, however, been limited to a few special cases involving relatively small macromolecules, unusually high-resolution ... approaches, including one that does not require high-resolution data, a related molecule as search fragment or heavier atoms and ...
CRUNCH2 - Karle-Hauptman determinants
International Tables for Crystallography (2012). Vol. F, Section 16.1.12.7, p. 429 [ doi:10.1107/97809553602060000850 ]
CRUNCH2 - Karle-Hauptman determinants 16.1.12.7. CRUNCH2 - Karle-Hauptman determinants The program CRUNCH2 is quite different to the other ... of some E-map recycling at the end to complete a substructure, CRUNCH2 operates entirely in reciprocal space by maximizing ...
[more results from section 16.1.12 in volume F]
Substructure solution for native sulfurs and halide soaks
International Tables for Crystallography (2012). Vol. F, Section 16.1.11, pp. 425-426 [ doi:10.1107/97809553602060000850 ]
... the incorporation of heavy-metal ions by soaking crystals with a low concentration of the metal salt for several hours. The ... not work well for all expression systems; the second had a low success rate. The improved quality of modern diffraction data ... sulfur atoms or from halide ions introduced by soaking with a high concentration of a halide (iodide or bromide) for ...
Substructure applications
International Tables for Crystallography (2012). Vol. F, Section 16.1.10.4, p. 425 [ doi:10.1107/97809553602060000850 ]
... known for some time that conventional direct methods can be a valuable tool for locating the positions of heavy-atom substructures ... when applied to such data. Dual-space direct methods provide a more robust foundation for handling such data, which are often ... care in data processing, especially if the values resulting from a MAD experiment are to be used. SHELXD is frequently ...
[more results from section 16.1.10 in volume F]
Recognizing solutions
International Tables for Crystallography (2012). Vol. F, Section 16.1.9.3, pp. 421-422 [ doi:10.1107/97809553602060000850 ]
... progress of current SnB jobs can be followed by monitoring a figure-of-merit histogram for the trial structures that have been processed (Fig. 16.1.9.2). A clear bimodal distribution of figure-of-merit values is a strong indication that a solution has, in fact, been ...
[more results from section 16.1.9 in volume F]
Utilizing Pattersons for better starts
International Tables for Crystallography (2012). Vol. F, Section 16.1.8, pp. 419-420 [ doi:10.1107/97809553602060000850 ]
... are present, it is possible to start recycling procedures from a set of atomic positions that are consistent with the Patterson ... This filter is currently implemented as follows in SHELXD. First, a sharpened Patterson function (Sheldrick et al., 1993) is calculated, and ... the top 200 (for example) non-Harker peaks further than a given minimum distance from the origin are selected, in ...
Resolution enhancement: the `free lunch' algorithm
International Tables for Crystallography (2012). Vol. F, Section 16.1.7, p. 419 [ doi:10.1107/97809553602060000850 ]
... 16.1.7. Resolution enhancement: the `free lunch' algorithm Direct methods take a set of phases, refine them and also determine new ones. ... to predict new amplitudes as well. If density modification of a real-space map is performed, then any process of real-space density modification will, following a Fourier transformation, give structure-factor amplitudes for reflections that ...
Fourier refinement
International Tables for Crystallography (2012). Vol. F, Section 16.1.6, p. 419 [ doi:10.1107/97809553602060000850 ]
... that can only be generated using the larger E magnitudes, a limited number of reflections are phased during the actual dual-space cycles. Working with a limited amount of data has the added advantage that less ... current trial structure is the `best' so far based on a figure of merit (either the minimal function or a ...
Random omit maps
International Tables for Crystallography (2012). Vol. F, Section 16.1.5.3, p. 419 [ doi:10.1107/97809553602060000850 ]
Random omit maps 16.1.5.3. Random omit maps A third peak-picking strategy involves selecting approximately of the top ... the common practice in macromolecular crystallography of omitting part of a structure from a Fourier calculation in the hope of finding an improved ...
[more results from section 16.1.5 in volume F]
Parameter shift
International Tables for Crystallography (2012). Vol. F, Section 16.1.4.3, p. 418 [ doi:10.1107/97809553602060000850 ]
... be used to minimize by varying the phases. So far, a seemingly simple algorithm, known as parameter shift (Bhuiya & Stanley, 1963 ... to reduce the value of the minimal function. For example, a typical phase-refinement stage consists of three iterations or scans through the reflection list, with each phase being shifted a maximum of two times by 90° in either the ...
[more results from section 16.1.4 in volume F]
Page: 1 2 Next | powered by |