Calculation of Different $R$ Values

$R$ values are output separately as single numbers for each classification and separately in intensity shells for each group of spectra. The overall $R$ value is stored in the variable $RNMR.

rfactor.inp

The following example shows a part of the output file, i.e., the calculated calibration factor and the $R$ value. The intensities are calculated from the coordinates by the calibration statement, and the optimal calibration factor is printed for each classification separately. The $R$ value is printed first for each classification and then for each group broken down in intensity shells.

 RELAx>    calibrate 
 CALIbrate>        quality 0.33  automatic off  reference all  group class 
 CALIbrate>    end 
 RELAX: intensities updated for calibration

             class   N(reference)   N(all)  calibration 
           ---------------------------------------------
             D300              0        23   .5220E+00
           ---------------------------------------------
 RELAx> 
 RELAx>    print threshold -0.1 end      {List all deviations and calculate R.} 
 Class D300: R-factor:    .6594E-01 R.m.s. difference:     .8038E-01
 RELAX: overall R-factor statistics 
           ------------------------------------------------------
             min. int.   max. int.    N   R-factor   r.m.s. diff 
           ------------------------------------------------------
             .2550E+01   .5100E+01    1   .4804E-01   .6302E-01
             .1275E+01   .2550E+01    4   .5346E-01   .8720E-01
             .6375E+00   .1275E+01    4   .4047E-01   .4735E-01
             .3187E+00   .6375E+00    9   .6331E-01   .7320E-01
             .1594E+00   .3187E+00    5   .1292E+00   .1204E+00
             .7969E-01   .1594E+00    4   .5022E-01   .5105E-01
           ------------------------------------------------------
             .0000E+00   .5100E+01   27   .6594E-01   .8038E-01
           ------------------------------------------------------
A local $R$ value can be calculated using the select option in the print statement. The following loop calculates the $R$ value for each residue in the sequence:
 
relaxation
    set echo off message off end
    for $id in id (name ca) loop rfac
        print 
            selection=(byres(id $id)) 
            threshold 9999 
        end
    end loop rfac
    set echo on message on end
end

Different types of local $R$ values can be calculated using the atom selection routine. For example, the $R$ value for the region around each residue can be calculated with the around option of the atom selection command (see Section 2.15).

Xplor-NIH 2023-11-10