diff --git a/doc/src/molecule.rst b/doc/src/molecule.rst index 0cfdd42337..0624180bd5 100644 --- a/doc/src/molecule.rst +++ b/doc/src/molecule.rst @@ -126,14 +126,50 @@ molecule (header keyword = inertia). Format of a molecule file """"""""""""""""""""""""" -The format of an individual molecule file is similar but -(not identical) to the data file read by the :doc:`read_data ` -commands, and is as follows. +The format of an individual molecule file looks similar but is +different than that of a data file read by the :doc:`read_data ` +commands. Here is a simple example for a TIP3P water molecule: + +.. code-block:: + + # Water molecule. TIP3P geometry + # header section: + 3 atoms + 2 bonds + 1 angles + + # body section: + Coords + + 1 0.00000 -0.06556 0.00000 + 2 0.75695 0.52032 0.00000 + 3 -0.75695 0.52032 0.00000 + + Types + + 1 1 # O + 2 2 # H + 3 2 # H + + Charges + + 1 -0.834 + 2 0.417 + 3 0.417 + + Bonds + + 1 1 1 2 + 2 1 1 3 + + Angles + + 1 1 2 1 3 A molecule file has a header and a body. The header appears first. The -first line of the header and thus of the molecule file is *always* skipped; -it typically contains a description of the file or a comment from the software -that created the file. +first line of the header and thus of the molecule file is *always* +skipped; it typically contains a description of the file or a comment +from the software that created the file. Then lines are read one line at a time. Lines can have a trailing comment starting with '#' that is ignored. There *must* be at least one @@ -158,25 +194,62 @@ appear if the value(s) are different than the default, except when defining a *body* particle, which requires setting the number of *atoms* to 1, and setting the *inertia* in a specific section (see below). -* N *atoms* = # of atoms N in molecule, default = 0 -* Nb *bonds* = # of bonds Nb in molecule, default = 0 -* Na *angles* = # of angles Na in molecule, default = 0 -* Nd *dihedrals* = # of dihedrals Nd in molecule, default = 0 -* Ni *impropers* = # of impropers Ni in molecule, default = 0 -* Nf *fragments* = # of fragments Nf in molecule, default = 0 -* Ninteger Ndouble *body* = # of integer and floating-point values - in body particle, default = 0 -* Mtotal *mass* = total mass of molecule -* Xc Yc Zc *com* = coordinates of center-of-mass of molecule -* Ixx Iyy Izz Ixy Ixz Iyz *inertia* = 6 components of inertia tensor of molecule + .. list-table:: + :header-rows: 1 + :widths: auto -For *mass*, *com*, and *inertia*, the default is for LAMMPS to -calculate this quantity itself if needed, assuming the molecules -consist of a set of point particles or finite-size particles (with a -non-zero diameter) that do not overlap. If finite-size particles in -the molecule do overlap, LAMMPS will not account for the overlap -effects when calculating any of these 3 quantities, so you should -pre-compute them yourself and list the values in the file. + * - Number(s) + - Keyword + - Meaning + - Default + * - N + - atoms + - # of atoms N in molecule + - 0 + * - Nb + - bonds + - # of bonds Nb in molecule + - 0 + * - Na + - angles + - # of angles Na in molecule + - 0 + * - Nd + - dihedrals + - # of dihedrals Nd in molecule + - 0 + * - Ni + - impropers + - # of impropers Ni in molecule + - 0 + * - Nf + - fragments + - # of fragments Nf in molecule + - 0 + * - Ninteger Ndouble + - body + - # of integer and floating-point values in body particle + - 0 + * - Mtotal + - mass + - total mass of molecule + - computed + * - Xc Yc Zc + - com + - coordinates of center-of-mass of molecule + - computed + * - Ixx Iyy Izz Ixy Ixz Iyz + - inertia + - 6 components of inertia tensor of molecule + - computed + +For *mass*, *com*, and *inertia*, the default is for LAMMPS to calculate +this quantity itself if needed, assuming the molecules consist of a set +of point particles or finite-size particles (with a non-zero diameter) +that do **not** overlap. If finite-size particles in the molecule +**do** overlap, LAMMPS will not account for the overlap effects when +calculating any of these 3 quantities, so you should pre-compute them +yourself and list the values in the file. The mass and center-of-mass coordinates (Xc,Yc,Zc) are self-explanatory. The 6 moments of inertia (ixx,iyy,izz,ixy,ixz,iyz)