3.26. GENSIN: Generate triplets and quartets
| trip | control generation of triplet invariants |
| quar | control generation of quartet invariants |
| gener | specify generator reflections |
| psical | use bdf  (h) and Fcalvalues to calculate  |
| control listing of invariant information | |
| change | modify reflection data from the input bdf |
| GENSIN | Option | Code | Arg | Def | |
| apply qpsi values | qpsi | include fragment estimate | |||
| nqpi | exclude fragment estimate | ||||
| attenuate large |E|'s | atte | attenuate |E|'s > 3.5 | |||
| natt | do not attenuate large |E|'s | ||||
max sin / of |E|'s | smax | s | restrict data sphere | from bdf | |
| type of E applied | etyp | n | type 1 or 2 from bdf | 1 | |
| dataset number | dset | n | 1 |
| trip | 1 | control generation of triplet invariants | |||
| do generate triplets | yes | ||||
| do not generate triplets | no | ||||
| 2 | min A value of generated triplet | 1.0 | |||
| or calculated based on E=1.5 (centro); E=1.8(noncentro) | |||||
| 3 | max unique triplets generated | auto | |||
| 4 | max triplets per generator | 500 |
| quar | 1 | control generation of quartet invariants | |||
| do generate quartets | yes | ||||
| do not generate quartets | no | ||||
| 2 | minimum B value of generated quartet | 1 | |||
| or calculated assuming E=1.8 (centro); E=2.2(noncentro) | |||||
| 3 | maximum unique quartets to be generated | auto | |||
| 4 | maximum quartets per generator | 500 | |||
| 5 | permitted cross-vectors for quartets | ||||
| all cross-vectors must be inside data sphere | insxv | ||||
| all cross-vectors are permitted | allxv | ||||
| one or more cross-vectors outside data sphere | outxv | ||||
| ignore cross-vectors and include all quartets | notxv | ||||
| 6 | minimum single cross-vector |E| accepted | 0 | |||
| 7 | maximum single cross-vector |E| accepted | 100 | |||
| 8 | low cross-vector sum limit (max for negative quartets) | 2.5 | |||
| 9 | high cross-vector sum limit (min for positive quartets) | 4 |
| gener | 1 | minimum |E|eligible as generator | auto |
| 2 | number of generator reflections (max 10,000) | auto | |
| 3 | minimum sin/ eligible as generator | 0 | |
| 4 | maximum sin/ eligible as generator | 2 | |
| 5 | minimum |E|-to- |E|ratio eligible as generator | 1 | |
| 6 | maximum number of (0) reflections allowed | auto |
| psical | 1 | select reflections used in structure invariant generation | |||
| select generators from hkl with input values | refine | ||||
| allow all reflections to be generators | extend | ||||
| 2 | bdf ID number of used to estimate of invariant | n750 | |||
| 3 | bdf ID number of Fcal used to estimate A and B | n751 |
| print [a] | 1 | print invariant summary for N generators | for all |
| 2 | first generator number of detailed listing | 0 | |
| 3 | last generator number of detailed listing | 0 | |
| 4 | maximum generator number listed in invariant blocks | 100 | |
| 5 | minimum A or B listed in invariant blocks | 0 | |
| Notes: a. A detailed listing of invariants for each generator in the range defined by fields 2 and 3. Only invariants where all reflections satisfy the constraints defined by fields 4 and 5 are listed. See example in the GENSIN. | |||