data has been taken from other studies (Table \[tab:otherdata\]). The ExoMol project has a specific methodology based on the use of spectroscopically-determined potential energy surfaces and [*ab initio*]{} dipole surfaces, which are combined with explicit variational treatments of the nuclear motion problem. For open shell systems these treatments involve explicit inclusion of spin-orbit and related curve-coupling effects; the project has developed a nuclear motion program, [Duo]{}, for treating coupled diatomic curves [@jt609]. For closed shell molecules a range of codes [@lr07; @jt338; @jt339; @07YuThJe.method; @15YaYuxx.method; @jt588] are used. These are all essentially based on finding near-exact solutions of the ro-vibrational Schrödinger equation for a given potential energy surface but the level of approximation increases with the size of the molecule considered.

Data from other sources arise from a variety of methodologies which range from completely [*ab initio*]{}, appropriate for systems with very few electrons, to largely empirical. Table \[tab:otherdata\] gives a pointer to the method used in each case; for full details the reader should consult the cited reference.

  Molecule    $N_{\rm iso}$    $T_{\rm max}$  $N_{elec}$    $N_{\rm lines}$ $^a$ DSName     Reference
  ---------- --------------- --------------- ------------ ---------------------- ---------- --------------------------------------
  BeH               1                   2000      1                       16 400 Yadin      Yadin [[*et al*]{}]{} [@jt529]
  MgH               3                   