SIR92 Phase

Preparation of data for PHASE routine


LIST n

The number of reflections at the top of the divergence map for which a list of the map is obtained. Default = no printout of the map.

TWOPHASE x

Two phase seminvariants are actively used if their concentration parameter is larger than x. If the directive is omitted x is assumed as the minimum value of G (or C) among the positive triplets.Very large values of x (say 1000 or so) hinder the active use of two-phase seminvariants.

ONEPHASE n

Number of strongest one-phase seminvariants to use in the starting set.Default value for n is chosen by seminvariants routine (up to a maximum of 3). If n is equal to zero, no seminvariant will be accepted.

ORIGIN n(i) phi(i)

Codes and phases of the reflections chosen by the user to fix the origin. The total number of reflections needed to fix the origin must be given (by default the origin is chosen by the program).

ENANTIOMORPH n

Code of the reflection chosen by the user to fix the enantiomorph (by default the enantiomorph is chosen by the program).

SYMBOLS n

The number of permuted phases (max 12). Default = 5.

PERMUTE n(i)

Codes of the permuted reflections chosen by the user (included in the number of required symbols, max 12).

SPECIALS n

The number of reflections with restricted phase to be permuted (included in the number of required symbols, max 12).

PHASE n(i) phi(i) wt(i)

Codes, phases and weights of reflections with known phase (max 200). If one card is not sufficient, the directive PHASE must be repeated in the other card(s).

TABLE

To print the table of alpha values.

TRIALS n(i)

To print the final phases for the specified trials.

MINFOM x n

x: the program automatically stops when a solution is found with CFOM > x . Default value = 0.95.
n: is the maximum number of phase sets (with the largest combined figure of merit - CFOM) to retain; (default value = 10)

RANDOM n

To use random phases starting sets.
n: is the number of random phases. If n is omitted, it is equal to one half of the strong reflections.

SEED n

Random generation seed. n must be an integer large value and must be odd. (Default 6753).

NOREJECT

Used to retain equivalent sets of phases.

TEST

Used to restart the random number generator using the default seed.

MAXTRIALS

Maximum number of trials when random approach is used. (Default 100).