1 .TH grompp 1 "Thu 26 Aug 2010" "" "GROMACS suite, VERSION 4.5"
3 grompp - makes a run input file
8 .BI "\-f" " grompp.mdp "
9 .BI "\-po" " mdout.mdp "
10 .BI "\-c" " conf.gro "
11 .BI "\-r" " conf.gro "
12 .BI "\-rb" " conf.gro "
13 .BI "\-n" " index.ndx "
14 .BI "\-p" " topol.top "
15 .BI "\-pp" " processed.top "
16 .BI "\-o" " topol.tpr "
17 .BI "\-t" " traj.trr "
18 .BI "\-e" " ener.edr "
20 .BI "\-[no]version" ""
24 .BI "\-[no]rmvsbds" ""
25 .BI "\-maxwarn" " int "
29 \&The gromacs preprocessor
30 \&reads a molecular topology file, checks the validity of the
31 \&file, expands the topology from a molecular description to an atomic
32 \&description. The topology file contains information about
33 \&molecule types and the number of molecules, the preprocessor
34 \&copies each molecule as needed.
35 \&There is no limitation on the number of molecule types.
36 \&Bonds and bond\-angles can be converted into constraints, separately
37 \&for hydrogens and heavy atoms.
38 \&Then a coordinate file is read and velocities can be generated
39 \&from a Maxwellian distribution if requested.
40 \&grompp also reads parameters for the mdrun
41 \&(eg. number of MD steps, time step, cut\-off), and others such as
42 \&NEMD parameters, which are corrected so that the net acceleration
44 \&Eventually a binary file is produced that can serve as the sole input
45 \&file for the MD program.
48 \&grompp uses the atom names from the topology file. The atom names
49 \&in the coordinate file (option \fB \-c\fR) are only read to generate
50 \&warnings when they do not match the atom names in the topology.
51 \&Note that the atom names are irrelevant for the simulation as
52 \&only the atom types are used for generating interaction parameters.
55 \&grompp uses a built\-in preprocessor to resolve includes, macros
56 \&etcetera. The preprocessor supports the following keywords:
73 \&The functioning of these statements in your topology may be modulated by
74 \&using the following two flags in your \fB mdp\fR file:
76 \&define = \-DVARIABLE1 \-DVARIABLE2
78 \&include = /home/john/doe
80 \&For further information a C\-programming textbook may help you out.
81 \&Specifying the \fB \-pp\fR flag will get the pre\-processed
82 \&topology file written out so that you can verify its contents.
85 \&If your system does not have a c\-preprocessor, you can still
86 \&use grompp, but you do not have access to the features
87 \&from the cpp. Command line options to the c\-preprocessor can be given
88 \&in the \fB .mdp\fR file. See your local manual (man cpp).
91 \&When using position restraints a file with restraint coordinates
92 \&can be supplied with \fB \-r\fR, otherwise restraining will be done
93 \&with respect to the conformation from the \fB \-c\fR option.
94 \&For free energy calculation the the coordinates for the B topology
95 \&can be supplied with \fB \-rb\fR, otherwise they will be equal to
96 \&those of the A topology.
99 \&Starting coordinates can be read from trajectory with \fB \-t\fR.
100 \&The last frame with coordinates and velocities will be read,
101 \&unless the \fB \-time\fR option is used.
102 \&Note that these velocities will not be used when \fB gen_vel = yes\fR
103 \&in your \fB .mdp\fR file. An energy file can be supplied with
104 \&\fB \-e\fR to read Nose\-Hoover and/or Parrinello\-Rahman coupling
105 \&variables. Note that for continuation it is better and easier to supply
106 \&a checkpoint file directly to mdrun, since that always contains
107 \&the complete state of the system and you don't need to generate
108 \&a new run input file. Note that if you only want to change the number
109 \&of run steps tpbconv is more convenient than grompp.
112 \&Using the \fB \-morse\fR option grompp can convert the harmonic bonds
113 \&in your topology to morse potentials. This makes it possible to break
114 \&bonds. For this option to work you need an extra file in your $GMXLIB
115 \&with dissociation energy. Use the \-debug option to get more information
116 \&on the workings of this option (look for MORSE in the grompp.log file
117 \&using less or something like that).
120 \&By default all bonded interactions which have constant energy due to
121 \&virtual site constructions will be removed. If this constant energy is
122 \¬ zero, this will result in a shift in the total energy. All bonded
123 \&interactions can be kept by turning off \fB \-rmvsbds\fR. Additionally,
124 \&all constraints for distances which will be constant anyway because
125 \&of virtual site constructions will be removed. If any constraints remain
126 \&which involve virtual sites, a fatal error will result.
128 To verify your run input file, please make notice of all warnings
129 \&on the screen, and correct where necessary. Do also look at the contents
130 \&of the \fB mdout.mdp\fR file, this contains comment lines, as well as
131 \&the input that \fB grompp\fR has read. If in doubt you can start grompp
132 \&with the \fB \-debug\fR option which will give you more information
133 \&in a file called grompp.log (along with real debug info). Finally, you
134 \&can see the contents of the run input file with the \fB gmxdump\fR
137 .BI "\-f" " grompp.mdp"
139 grompp input file with MD parameters
141 .BI "\-po" " mdout.mdp"
143 grompp input file with MD parameters
145 .BI "\-c" " conf.gro"
147 Structure file: gro g96 pdb tpr etc.
149 .BI "\-r" " conf.gro"
151 Structure file: gro g96 pdb tpr etc.
153 .BI "\-rb" " conf.gro"
155 Structure file: gro g96 pdb tpr etc.
157 .BI "\-n" " index.ndx"
161 .BI "\-p" " topol.top"
165 .BI "\-pp" " processed.top"
169 .BI "\-o" " topol.tpr"
171 Run input file: tpr tpb tpa
173 .BI "\-t" " traj.trr"
175 Full precision trajectory: trr trj cpt
177 .BI "\-e" " ener.edr"
183 Print help info and quit
185 .BI "\-[no]version" "no "
186 Print version info and quit
188 .BI "\-nice" " int" " 0"
194 .BI "\-time" " real" " \-1 "
195 Take frame at or first after this time.
197 .BI "\-[no]rmvsbds" "yes "
198 Remove constant bonded interactions with virtual sites
200 .BI "\-maxwarn" " int" " 0"
201 Number of allowed warnings during input processing
203 .BI "\-[no]zero" "no "
204 Set parameters for bonded interactions without defaults to zero instead of generating an error
206 .BI "\-[no]renum" "yes "
207 Renumber atomtypes and minimize number of atomtypes
212 More information about \fBGROMACS\fR is available at <\fIhttp://www.gromacs.org/\fR>.