1 .TH genbox 1 "Thu 16 Oct 2008"
3 genbox - solvates a system
8 .BI "-cp" " protein.gro "
9 .BI "-cs" " spc216.gro "
10 .BI "-ci" " insert.gro "
12 .BI "-p" " topol.top "
24 Genbox can do one of 3 things:
27 1) Generate a box of solvent. Specify -cs and -box. Or specify -cs and
28 -cp with a structure file with a box, but without atoms.
31 2) Solvate a solute configuration, eg. a protein, in a bath of solvent
37 The box specified in the solute coordinate file (
43 If you want the solute to be centered in the box,
46 has sophisticated options
47 to change the box dimensions and center the solute.
48 Solvent molecules are removed from the box where the
49 distance between any atom of the solute molecule(s) and any atom of
50 the solvent molecule is less than the sum of the VanderWaals radii of
51 both atoms. A database (
53 ) of VanderWaals radii is
54 read by the program, atoms not in the database are
55 assigned a default distance
62 ) of extra molecules (
66 The program iterates until
69 have been inserted in the box. To test whether an insertion is
70 successful the same VanderWaals criterium is used as for removal of
71 solvent molecules. When no appropriately
72 sized holes (holes that can hold an extra molecule) are available the
77 times before giving up.
78 Increase -try if you have several small holes to fill.
81 The default solvent is Simple Point Charge water (SPC), with coordinates
85 solvents are also supported, as well as mixed solvents. The
86 only restriction to solvent types is that a solvent molecule consists
87 of exactly one residue. The residue information in the coordinate
88 files is used, and should therefore be more or less consistent.
89 In practice this means that two subsequent solvent molecules in the
90 solvent coordinate file should have different residue number.
91 The box of solute is built by stacking the coordinates read from
92 the coordinate file. This means that these coordinates should be
93 equlibrated in periodic boundary conditions to ensure a good
94 alignment of molecules on the stacking interfaces.
97 The program can optionally rotate the solute molecule to align the
98 longest molecule axis along a box edge. This way the amount of solvent
99 molecules necessary is reduced.
100 It should be kept in mind that this only works for
101 short simulations, as eg. an alpha-helical peptide in solution can
102 rotate over 90 degrees, within 500 ps. In general it is therefore
103 better to make a more or less cubic box.
106 Setting -shell larger than zero will place a layer of water of
107 the specified thickness (nm) around the solute. Hint: it is a good
108 idea to put the protein in the center of a box first (using editconf).
112 Finally, genbox will optionally remove lines from your topology file in
113 which a number of solvent molecules is already added, and adds a
114 line with the total number of solvent molecules in your coordinate file.
116 .BI "-cp" " protein.gro"
118 Structure file: gro g96 pdb tpr tpb tpa
120 .BI "-cs" " spc216.gro"
122 Structure file: gro g96 pdb tpr tpb tpa
124 .BI "-ci" " insert.gro"
126 Structure file: gro g96 pdb tpr tpb tpa
130 Structure file: gro g96 pdb
132 .BI "-p" " topol.top"
138 Print help info and quit
140 .BI "-nice" " int" " 19"
143 .BI "-box" " vector" " 0 0 0"
146 .BI "-nmol" " int" " 0"
147 no of extra molecules to insert
149 .BI "-try" " int" " 10"
150 try inserting -nmol*-try times
152 .BI "-seed" " int" " 1997"
153 random generator seed
155 .BI "-vdwd" " real" " 0.105 "
156 default vdwaals distance
158 .BI "-shell" " real" " 0 "
159 thickness of optional water layer around solute
161 .BI "-maxsol" " int" " 0"
162 maximum number of solvent molecules to add if they fit in the box. If zero (default) this is ignored
165 keep velocities from input solute and solvent
168 \- Molecules must be whole in the initial configurations.