btw in the German monolingual dictionary these items are listed as follows:
<!-- attachable prefix in separable verb -->
<pardef n="separable_particle__atp">
  <e r="RL"><p><l>ab</l>          <r>#<b/>ab<s n="atp"/></r></p></e>
  <e r="RL"><p><l>acht</l>        <r>#<b/>acht<s n="atp"/></r></p></e>
  <e r="RL"><p><l>an</l>          <r>#<b/>an<s n="atp"/></r></p></e>
  <e r="RL"><p><l>aneinander</l>  <r>#<b/>aneinander<s n="atp"/></r></p></e>
  <e r="RL"><p><l>auf</l>         <r>#<b/>auf<s n="atp"/></r></p></e>
  <e r="RL"><p><l>aufeinander</l> <r>#<b/>aufeinander<s n="atp"/></r></p></e>
  <e r="RL"><p><l>aufrecht</l>    <r>#<b/>aufrecht<s n="atp"/></r></p></e>