LEAPR::Card4 description references nonexistent entry

[ameliajo]

pg. 667 Card4 description discusses "isym", which exists in leapr.f90 but and somehow related to isabt but isn't an input itself

[paulromano]

Assuming that isym is the same as isabt, it's still not even clear which value corresponds to symmetric and asymmetric. The card says 0=s, 1=ss, def=0. Does ss mean "symmetric S" or "script S" or something else? Nowhere does the documentation describe what ss mean.

[whaeck]

From what I gather, isym is the equivalent of LASYM in MF7, whether or not the S(a,b) are symmetric in beta. However, isym can take the values of 0,1,2, 3 while LASYM can only be 0 or 1.
When looking in the coding, I see the following meanings for isym:
isym = 0: only positive beta values and S exp(-beta/2) is tabulated in the ENDF file
isym = 1: negative and positive beta values and S exp(-beta/2) is tabulated in the ENDF file
isym = 2: only positive beta values and S is tabulated in the ENDF file
isym = 3: negative and positive beta values and S is tabulated in the ENDF file
I still have to look into this further, but page 657 of the NJOY manual gives more info (formulas 517 and 518).

[paulromano]

Card 4 in LEAPR doesn't have isym as a parameter though; it asks for isabt which is ill-defined (not clear if ss means symmetric or asymmetric).

[whaeck]

I forgot to mention that isym is calculated from isabt:

   isym=0
   if (ncold.ne.0) isym=1
   if (isabt.eq.1) isym=isym+2

isabt=0 thus seems corresponds to the traditional ENDF way while isabt=1 will store the values without the exp(-beta/2) factor. Either way, isym=2,3 leads to ENDF files that cannot be processed with thermr.