diff --git a/doc/data/index.md b/doc/data/index.md
index 3e3582abf6..256b263aac 100644
--- a/doc/data/index.md
+++ b/doc/data/index.md
@@ -2,7 +2,7 @@
 
 In this section, we will introduce how to convert the DFT labeled data into the data format used by DeePMD-kit.
 
-The DeePMD-kit organize data in `systems`. Each `system` is composed by a number of `frames`. One may roughly view a `frame` as a snap short on an MD trajectory, but it does not necessary come from an MD simulation. A `frame` records the coordinates and types of atoms, cell vectors if the periodic boundary condition is assumed, energy, atomic forces and virial. It is noted that the `frames` in one `system` share the same number of atoms with the same type.
+The DeePMD-kit organize data in `systems`. Each `system` is composed by a number of `frames`. One may roughly view a `frame` as a snap shot on an MD trajectory, but it does not necessary come from an MD simulation. A `frame` records the coordinates and types of atoms, cell vectors if the periodic boundary condition is assumed, energy, atomic forces and virial. It is noted that the `frames` in one `system` share the same number of atoms with the same type.
 
 - [System](system.md)
 - [Formats of a system](data-conv.md)
diff --git a/doc/data/index.rst b/doc/data/index.rst
index d5fa62648a..c9af5011af 100644
--- a/doc/data/index.rst
+++ b/doc/data/index.rst
@@ -2,7 +2,7 @@ Data
 ====
 In this section, we will introduce how to convert the DFT labeled data into the data format used by DeePMD-kit.
 
-The DeePMD-kit organize data in :code:`systems`. Each :code:`system` is composed by a number of :code:`frames`. One may roughly view a :code:`frame` as a snap short on an MD trajectory, but it does not necessary come from an MD simulation. A :code:`frame` records the coordinates and types of atoms, cell vectors if the periodic boundary condition is assumed, energy, atomic forces and virial. It is noted that the :code:`frames` in one :code:`system` share the same number of atoms with the same type.
+The DeePMD-kit organize data in :code:`systems`. Each :code:`system` is composed by a number of :code:`frames`. One may roughly view a :code:`frame` as a snap shot on an MD trajectory, but it does not necessary come from an MD simulation. A :code:`frame` records the coordinates and types of atoms, cell vectors if the periodic boundary condition is assumed, energy, atomic forces and virial. It is noted that the :code:`frames` in one :code:`system` share the same number of atoms with the same type.
 
 .. toctree::
    :maxdepth: 1