To my knowledge there is no such tool built-in, because a fully expanded parameter table is not stored in the `tpr`

files.

Instead, there is a list of bonds, stored with the atoms involved, the function type (e.g. Angle, Dihedral, improper) and an interaction type (a integer) - and there is a list of interaction type, from 0 to N, with parameters for the bond. During the simulation, for each bond, the parameters are looked-up in the interaction type table.

You can get both the interaction function table, and the bond table, with `gmx dump -s runfile.tpr`

, and associate them with a bit of scripting (probably, regexp).

The interaction table looks like this:

```
functype[118]=LJ_SR, c6= 0.00000000e+00, c12= 0.00000000e+00
functype[119]=LJ_SR, c6= 9.28111258e-04, c12= 3.09248890e-06
functype[120]=LJ_SR, c6= 1.21614011e-02, c12= 8.83721732e-05
functype[121]=BONDS, b0A= 1.52200e-01, cbA= 2.65266e+05, b0B= 1.52200e-01, cbB= 2.65266e+05
functype[127]=ANGLES, thA= 1.09500e+02, ctA= 2.92880e+02, thB= 1.09500e+02, ctB= 2.92880e+02
functype[128]=ANGLES, thA= 1.09500e+02, ctA= 4.18400e+02, thB= 1.09500e+02, ctB= 4.18400e+02
functype[137]=ANGLES, thA= 1.11100e+02, ctA= 5.27184e+02, thB= 1.11100e+02, ctB= 5.27184e+02
functype[138]=ANGLES, thA= 1.09500e+02, ctA= 3.34720e+02, thB= 1.09500e+02, ctB= 3.34720e+02
functype[139]=ANGLES, thA= 1.17000e+02, ctA= 5.85760e+02, thB= 1.17000e+02, ctB= 5.85760e+02
functype[140]=ANGLES, thA= 1.26000e+02, ctA= 6.69440e+02, thB= 1.26000e+02, ctB= 6.69440e+02
functype[141]=PDIHS, phiA= 0.00000000e+00, cpA= 3.34719992e+00, phiB= 0.00000000e+00, cpB= 3.34719992e+00, mult=1
functype[142]=PDIHS, phiA= 1.80000000e+02, cpA= 3.34719986e-01, phiB= 1.80000000e+02, cpB= 3.34719986e-01, mult=3
functype[143]=PDIHS, phiA= 1.80000000e+02, cpA= 1.04600000e+01, phiB= 1.80000000e+02, cpB= 1.04600000e+01, mult=2
functype[144]=PDIHS, phiA= 0.00000000e+00, cpA= 8.36800003e+00, phiB= 0.00000000e+00, cpB= 8.36800003e+00,
functype[162]=LJ14, c6A= 4.31535700e-05, c12A= 5.36973888e-09, c6B= 4.31535700e-05, c12B= 5.36973888e-09
functype[163]=LJ14, c6A= 1.41338352e-03, c12A= 2.18213040e-06, c6B= 1.41338352e-03, c12B= 2.18213040e-06
```

and the list of bond like this:

```
Bond:
nr: 39
iatoms:
0 type=121 (BONDS) 0 4
1 type=122 (BONDS) 4 5
2 type=123 (BONDS) 4 6
3 type=124 (BONDS) 6 8
4 type=125 (BONDS) 8 10
5 type=121 (BONDS) 8 19
6 type=125 (BONDS) 10 13
7 type=121 (BONDS) 13 16
8 type=126 (BONDS) 16 17
9 type=126 (BONDS) 16 18
10 type=122 (BONDS) 19 20
11 type=123 (BONDS) 19 21
12 type=124 (BONDS) 21 23
G96Bond:
nr: 0
Morse:
nr: 0
Cubic Bonds:
nr: 0
Restraint Pot.:
nr: 0
Angle:
nr: 180
iatoms:
0 type=127 (ANGLES) 1 0 2
1 type=127 (ANGLES) 1 0 3
2 type=128 (ANGLES) 1 0 4
3 type=127 (ANGLES) 2 0 3
4 type=128 (ANGLES) 2 0 4
5 type=128 (ANGLES) 3 0 4
6 type=129 (ANGLES) 0 4 5
7 type=130 (ANGLES) 0 4 6
8 type=131 (ANGLES) 5 4 6
9 type=132 (ANGLES) 4 6 7
```

You store the interaction table, then for each bond you lookup the interaction using the, e.g., `type=127`

label, then probably store them then output them as expected for a `.top`

file.

Possibly such a script already exist somewhere on the web.