SAXNS PDDF Calculator

This script estimates the theoretical SAXS PDDF or P(r) function of a given structure from its PDB file.

The Output is scaled so that Σ_iP(r_i)= i (Number of bins)
This ensures that the value in each bin is independent of the number of bins and simplifies the comparison of multiple P(r) curves.

Select the PDB file:

Plot Quality: (% error in each bin)

Plot size (png)

Chain Selection: A only ALL

GNOM/GIFT P(r): (Optional)

Number of P(r_i) bins: (Min 1Å per bin)

Your e-mail:

Calculate PDDF:

Caveats

The following functions are not implemented:
- Chain Selection
- Smoothing of data
- Comparison with GNOM/BayesApp P(r)
Note: Waters in the PDB are ignored ::
There is no hydration shell in the P(r) calculation.
Wide bins (too few) will result in a skewed P(r) curve.
Server Gateway "Time-Out" on long calculations: Time α (NBins) / (%Quality).
Note: CPU time is independent of #atoms.