3.63. SIMPEL: Symbolic-addition phasing
| invar | structure invariant options |
| start | selection of starting phases options |
| phase | defining starting phase |
| print options of different stages | |
| symbad | symbolic addition procedure options |
| setfom | define figure of merit parameters |
| psets | specify phase sets to be output |
| SIMPEL | 1 | number of generators eligible for starting set | 25% of total |
| 2 | number of generators eligible for divergence | 50% of total | |
| 3 | number of generators eligible for phasing | 100% of total | |
| 4 | minimum |E| value of input generators | from bdf .inv | |
| 5 | data set number of |E|'s | 1 | |
| 6 | number of phase sets output on output archive bdf | 4 |
| start | 1 | control invariants used in con/divergence process | |||
| use triplets only in starting process | trip | ||||
| use quartets only in starting process | quar | ||||
| use triplets and quartets in starting process | all | ||||
| 2 | probability term used in convergence process | ||||
| use (1) described in Step 1 | 1 | ||||
| use (2) described in Step 1 | 2 | ||||
| 3 | threshold ALTHR to accept one invariant | 10th-largest  | |||
| 4 | factor used to reduce [alpha] using  ][alpha; | 1 | |||
| 5 | number of symbols to be assigned in convergence process | if no phase lines entered | 4 | ||
| otherwise | 0 |
| invar | 1 | invariant types to be used in symbolic addition | |||
| use triplets only | trip | ||||
| use quartets only | quar | ||||
| use triplets and quartets | all | ||||
| 2 | minimum A of triplets used | from bdf inv | |||
| 3 | minimum B of quartets used | from bdf inv | |||
| 4 | maximum triplets allowed per generator | 100 | |||
| 5 | maximum quartets allowed per generator | 100 | |||
| 6 | low crossvector sum limit for quartets | 25% of max XV-sum (up to max of 2.5) | |||
| 7 | high cross vector sum limit for quartets | 75% of max XV-sum (to min of 4.0) | |||
| 8 |  phase correction applied to negative quartets in degrees | if no fragment | 180 | ||
| otherwise | 0 |
| print [a] | 1- | print invariant statistics and sums | invar | ||
| print converge order of generators | converg | ||||
| print extension of starting set into converge set | extend | ||||
| print extension of starting set into diverge set | diverg | ||||
| print symbolic addition extension process | symbad | ||||
| print application of accepted symbols to all |E|'s | correl | ||||
| print figure-of-merit details | fomtest | ||||
| print phase sets output to bdf | bdfout | ||||
| Notes: a. Entering no options implies that all print options are invoked. | |||||
| symbad | 1 | probability factor used in symbolic addition | |||
| use sum of weighted 's (see Step 3.) | wa | ||||
| use sum of 's and invariant count | an | ||||
| 2 | acceptance procedure if multiple symbols generated | ||||
| accept most probable indication | mult | ||||
| reject all but single symbol indication | sing | ||||
| 3 | no. of generators added in blocks to the symbolic process | 100 | |||
| 4 | acceptance threshold of weight for wa option | 0.3 |
| setfom | 1 | number of top phase sets applied in FOM tests [a] | 16 |
| 2 | optimum value for QFOM | 0.75 | |
| 3 | weight of QFOM in CFOM and AMOS | 1 | |
| 4 | optimum value of RFOM | 1 | |
| 5 | weight of RFOM in CFOM and AMOS | 1 | |
| 6 | optimum value of RFAC FOM | 0.25 | |
| 7 | weight of RFAC in CFOM and AMOS | 1 | |
| 8 | optimum value of PSI0 FOM | 0.75 | |
| 9 | weight of PSI0 in CFOM and AMOS | 1 | |
| 10 | optimum value of NEGQ FOM | 60 | |
| 11 | weight of NEGQ in CFOM and AMOS | 1 | |
| Notes: a. Phase sets are presorted based on the max correlation with the symbolic phases. | |||
| phase | 1-3 | hkl indices | |||
| 4 | input phase (in degrees) | assign as new symbolic phase | |||
| 5 | Phase status option | Code | |||
| assign as origin defining phase | odr | ||||
| assign as enantiomorph phase | edr | ||||
| assign as symbolic phase [a] | sym | ||||
| assign as numeric phase1 | set | ||||
| remove phase from phasing process | nul | ||||
| Notes: a. The default is sym if field 4 is void; set is default if field 4 is numeric. | |||||