| VERSION 4.6 |
This is simple tool to compute SANS spectra using Debye formula It currently uses topology file (since it need to assigne element for each atom)
Parameters:
-pr Computes normalized g(r) function averaged over trajectory
-prframe Computes normalized g(r) function for each frame
-sq Computes SANS intensity curve averaged over trajectory
-sqframe Computes SANS intensity curve for each frame
-startq Starting q value in nm
-endq Ending q value in nm
-qstep Stepping in q space
Note: When using Debye direct method computational cost increases as 1/2 * N * (N - 1) where N is atom number in group of interest
WARNING: If sq or pr specified this tool can produce large number of files! Up to two times larger than number of frames!
| option | filename | type | description |
|---|---|---|---|
| -s | topol.tpr | Input | Run input file: tpr tpb tpa |
| -f | traj.xtc | Input | Trajectory: xtc trr trj gro g96 pdb cpt |
| -n | index.ndx | Input, Opt. | Index file |
| -d | nsfactor.dat | Input, Opt. | Generic data file |
| -pr | pr.xvg | Output | xvgr/xmgr file |
| -sq | sq.xvg | Output | xvgr/xmgr file |
| -prframe | prframe.xvg | Output, Opt. | xvgr/xmgr file |
| -sqframe | sqframe.xvg | Output, Opt. | xvgr/xmgr file |
| option | type | default | description |
|---|---|---|---|
| -[no]h | bool | no | Print help info and quit |
| -[no]version | bool | no | Print version info and quit |
| -nice | int | 19 | Set the nicelevel |
| -b | time | 0 | First frame (ps) to read from trajectory |
| -e | time | 0 | Last frame (ps) to read from trajectory |
| -dt | time | 0 | Only use frame when t MOD dt = first time (ps) |
| -tu | enum | ps | Time unit: fs, ps, ns, us, ms or s |
| -xvg | enum | xmgrace | xvg plot formatting: xmgrace, xmgr or none |
| -mode | enum | direct | Mode for sans spectra calculation: direct or mc |
| -mcover | real | -1 | Monte-Carlo coverage should be -1(default) or (0,1] |
| -[no]pbc | bool | yes | Use periodic boundary conditions for computing distances |
| -startq | real | 0 | Starting q (1/nm) |
| -endq | real | 2 | Ending q (1/nm) |
| -qstep | real | 0.01 | Stepping in q (1/nm) |
| -seed | int | 0 | Random seed for Monte-Carlo |
| -nt | int | 8 | Number of threads to start |